From b01646cfd8462dcd61e746d89dcc19dd3847ea17 Mon Sep 17 00:00:00 2001
From: dev <info@activething.com>
Date: Wed, 26 Aug 2026 05:55:35 +0200
Subject: [PATCH] =?UTF-8?q?feat(soma)!:=20fase=20C2c=20=E2=80=94=20el=20ef?=
 =?UTF-8?q?ecto=20syncAttrs=20muere;=20una=20tuber=C3=ADa,=20cero=20ambig?=
 =?UTF-8?q?=C3=BCedad?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Cierre de la fase C del P0: tras C2a (la bolsa resuelve el contrato) y C2b
(una sola computación), el efecto era doble-escritura idempotente sin
función. Se retira entero: `syncPartAttrs`, el flag del tipo y las ~71
registraciones que lo pasaban (tabs-provider y radio-group-provider viajaron
en `8ac23047f` del eje theming con la retirada declarada en su cuerpo —
coordinación por canal entre sesiones, historia completa desde ambos lados).
El único escritor imperativo sancionado que queda es el prewrite de
`trigger` (un commit que el morfo declara).

La PRIMERA pasada de la suite completa de la historia (nadie la corría — el
hallazgo original del informe demostrándose solo) destapó la cola: ~258
asserts en 34 ficheros de test de provider (jsdom, elementos sueltos)
ejercitaban las escrituras DOM del efecto retirado, no el contrato. Todos
re-firmados a asserts de bolsa, con tres leyes que salieron del trabajo:

- la bolsa entrega valores CRUDOS (número 20, no '20'; booleans donde el
  getter los produce) — Svelte stringifica al render, el DOM no cambia;
- una AUSENCIA se aserta contra la bolsa del PART (`'x' in props === false`),
  no contra un getter de provider que añada la clave explícita `undefined`;
- el prewrite (`data-last-action`) SIGUE siendo assert de DOM — es el
  escritor imperativo que sobrevive.

De la misma pasada: `skin-media-player` entra en `COMPETING_ROOTS` de
lint.test (viste el contrato de media-player, clase audio-player — nació sin
registrarse y nada lo corría), y los ~10 comentarios que describían el
efecto (dialog-001, sticky, knob, field, media-player, editable, anchor-nav)
pasan a describir la bolsa, verificados spread a spread antes de tocar nada.

Verificación: runtime 49/49 · ssr-contract 6/6 · morfo:check 161/161
post-strip («All routed morfos validate» — el detector definitivo) · los 34
ficheros re-firmados en verde · suite completa con únicos rojos residuales
los flaky de carga ya adjudicados (timeouts que pasan en solitario) ·
svelte-check src/ a 0 (71 = ledger exacto de web/).

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
---
 docs/process/CONTINUE-audit-p0.md             | 156 ++++++++++++
 src/uix/eidos/lint.test.ts                    |   5 +-
 src/uix/morfo/components/dialog.ts            |   6 +-
 .../accordion-provider.svelte.test.ts         |   5 +-
 .../accordion/accordion-provider.svelte.ts    |  18 +-
 .../alert-dialog-provider.svelte.test.ts      |   5 +-
 .../alert-dialog-provider.svelte.ts           |  11 +-
 .../anchor-nav/anchor-nav-provider.svelte.ts  |  15 +-
 .../announce/announce-provider.svelte.test.ts |  26 +-
 .../announce/announce-provider.svelte.ts      |   3 +-
 .../aura/aura-provider.svelte.test.ts         |   7 +-
 .../components/aura/aura-provider.svelte.ts   |  18 +-
 .../breadcrumb-provider.svelte.test.ts        |  33 +--
 .../breadcrumb/breadcrumb-provider.svelte.ts  |  16 +-
 .../button/button-provider.svelte.ts          |   3 +-
 .../chat-composer-provider.svelte.ts          |  24 +-
 .../chat-list/chat-list-provider.svelte.ts    |  25 +-
 .../chat-log/chat-log-provider.svelte.ts      |  25 +-
 .../chat-message-provider.svelte.ts           |  36 +--
 .../chat-typing-provider.svelte.ts            |  12 +-
 .../checkbox/checkbox-provider.svelte.ts      |  13 +-
 .../clipboard-provider.svelte.test.ts         |  11 +-
 .../clipboard/clipboard-provider.svelte.ts    |   9 +-
 .../collapsible-provider.svelte.test.ts       |  41 ++--
 .../collapsible-provider.svelte.ts            |   9 +-
 .../combobox/combobox-provider.svelte.ts      |   3 +-
 .../cropper/cropper-provider.svelte.ts        |  23 +-
 .../css-field/css-field-provider.svelte.ts    |   6 +-
 .../date-field/date-field-provider.svelte.ts  |   6 +-
 .../date-range-field-provider.svelte.ts       |   6 +-
 .../dialog/dialog-provider.svelte.test.ts     |  10 +-
 .../dialog/dialog-provider.svelte.ts          |  58 ++---
 .../drawer/drawer-provider.svelte.test.ts     |   8 +-
 .../drawer/drawer-provider.svelte.ts          |  38 ++-
 .../editable/editable-provider.svelte.test.ts |   9 +-
 .../editable/editable-provider.svelte.ts      |  15 +-
 .../emoji-picker-provider.svelte.ts           |  18 +-
 .../feed/feed-provider.svelte.test.ts         |  39 +--
 .../components/feed/feed-provider.svelte.ts   |  15 +-
 .../field-langs-provider.svelte.ts            |   8 +-
 .../field/field-provider.svelte.test.ts       |  25 +-
 .../components/field/field-provider.svelte.ts |  27 +--
 .../float-panel-provider.svelte.ts            | 119 ++++++----
 .../form/form-provider.svelte.test.ts         |   5 +-
 .../components/form/form-provider.svelte.ts   |   3 +-
 .../gradient-builder-provider.svelte.ts       |   8 +-
 .../gradient-picker-provider.svelte.ts        |   9 +-
 .../image-adjustments-provider.svelte.ts      |  29 +--
 .../image-picker-provider.svelte.ts           |  20 +-
 .../components/knob/knob-provider.svelte.ts   |  19 +-
 .../mask-field-provider.svelte.test.ts        |   5 +-
 .../mask-field/mask-field-provider.svelte.ts  |   3 +-
 .../media-player-provider.svelte.test.ts      |   8 +-
 .../media-player-provider.svelte.ts           |   7 +-
 .../meter/meter-provider.svelte.test.ts       |  40 ++--
 .../components/meter/meter-provider.svelte.ts |   7 +-
 .../nav-tree/nav-tree-provider.svelte.ts      |   5 +-
 .../number-field-provider.svelte.ts           |   6 +-
 .../pagination-provider.svelte.test.ts        |  18 +-
 .../pagination/pagination-provider.svelte.ts  |   6 +-
 .../palabras/palabras-provider.svelte.test.ts |  37 +--
 .../palabras/palabras-provider.svelte.ts      |  82 +++----
 .../password-field-provider.svelte.ts         |  20 +-
 .../popover/popover-provider.svelte.test.ts   |  34 ++-
 .../popover/popover-provider.svelte.ts        | 132 +++++------
 .../progress/progress-provider.svelte.test.ts |  47 ++--
 .../progress/progress-provider.svelte.ts      |  13 +-
 .../rating-group-provider.svelte.test.ts      |  40 ++--
 .../rating-group-provider.svelte.ts           |   6 +-
 .../search-field-provider.svelte.test.ts      |  11 +-
 .../search-field-provider.svelte.ts           |   3 +-
 .../select/select-provider.svelte.ts          |  11 +-
 .../slider/slider-provider.svelte.test.ts     |  19 +-
 .../slider/slider-provider.svelte.ts          |  12 +-
 .../splitter/splitter-provider.svelte.test.ts |  31 ++-
 .../splitter/splitter-provider.svelte.ts      |  10 +-
 .../stepper/stepper-provider.svelte.test.ts   |  34 ++-
 .../stepper/stepper-provider.svelte.ts        |  18 +-
 .../sticky/sticky-provider.svelte.test.ts     |  34 ++-
 .../sticky/sticky-provider.svelte.ts          |  10 +-
 .../switch/switch-provider.svelte.ts          |   6 +-
 .../tag-group-provider.svelte.test.ts         |  11 +-
 .../tag-group/tag-group-provider.svelte.ts    |   9 +-
 .../tags-input-provider.svelte.test.ts        |  13 +-
 .../tags-input/tags-input-provider.svelte.ts  |   6 +-
 .../textarea/textarea-provider.svelte.ts      |  18 +-
 .../time-field/time-field-provider.svelte.ts  |   6 +-
 .../time-range-field-provider.svelte.ts       |   6 +-
 .../toast/toast-provider.svelte.test.ts       |  34 +--
 .../components/toast/toast-provider.svelte.ts |  24 +-
 .../toggle-group-provider.svelte.ts           |   6 +-
 .../toggle/toggle-provider.svelte.test.ts     |  19 +-
 .../toggle/toggle-provider.svelte.ts          |   3 +-
 .../toolbar/toolbar-provider.svelte.test.ts   |  20 +-
 .../toolbar/toolbar-provider.svelte.ts        |  18 +-
 .../tooltip/tooltip-provider.svelte.test.ts   |  10 +-
 .../tooltip/tooltip-provider.svelte.ts        |  18 +-
 .../virtual-grid-provider.svelte.ts           |  10 +-
 .../virtual-list-provider.svelte.ts           |  18 +-
 .../waveform/waveform-provider.svelte.test.ts |  11 +-
 .../waveform/waveform-provider.svelte.ts      |   3 +-
 src/uix/soma/runtime.svelte.test.ts           | 223 ++++++++----------
 src/uix/soma/runtime.svelte.ts                |  78 ++----
 103 files changed, 1131 insertions(+), 1206 deletions(-)
 create mode 100644 docs/process/CONTINUE-audit-p0.md

diff --git a/docs/process/CONTINUE-audit-p0.md b/docs/process/CONTINUE-audit-p0.md
new file mode 100644
index 000000000..23af11d6c
--- /dev/null
+++ b/docs/process/CONTINUE-audit-p0.md
@@ -0,0 +1,156 @@
+# CONTINUE — P0 de la auditoría arquitectónica (handoff, act. 2026-08-26 madrugada)
+
+**Estado**: **P0 = A + B + C, EJECUTADO Y VERIFICADO.** Fase A cerrada (árbol en
+verde con instrumento afinado) · fase B cerrada (la puerta existe, sabe fallar y
+pasó en verde sobre HEAD; hook con fuente commiteada) · fase C cerrada entera
+(C2a bolsa=contrato · C2b renderProps muerto · C2c efecto muerto — **una sola
+tubería de attrs**). **D (desacoplar emit del handler) quedó FUERA de P0 por
+decisión de diseño**: la versión barata (D-lite) creaba un contrato condicional
+(`TriggerResult.id` a-veces-definido) y se retiró; la correcta es **D-full**
+(`emit()` → `{id, settled}`) y reabre el eje sema con su handoff — ver §D abajo.
+
+**Origen**: informe de auditoría (artifact `Auditoría ActiveUix`,
+https://claude.ai/code/artifact/02076a7a-9a51-4c89-a610-dfd2f6948954) — 70
+hallazgos, 10 verificados adversarialmente (7 confirmados / 3 refutados), dos
+comparativas de mercado. El plan P0→P3 vive en su §5.
+
+## Commits de este eje (todos en `alpha-0.1-background`, sin push)
+
+- `58fa3021c` — fase A: `close` huérfano de connection (4 errores) · stepper
+  `'completed'`→`'complete'` (el test pineaba la deriva) · langs stop/record.
+- `2ec018107` — fase B: `check:gate` (src/=0 duro; web/ contra ledger menguante
+  `scripts/check-debt.ts`, 34 ficheros/71 errores congelados) · `eidos:lint` ·
+  `gate` (SIN `lint` — deliberado, ver deuda) · fuente del hook en
+  `scripts/hooks/pre-push` · `.prettierrc` endOfLine:auto.
+- `3ca138e91` — C2a: `partPropsForRegistration` resuelve el contrato entero;
+  nace `ssr-contract.test.ts` (rojo antes, 6/6 después); pin viejo re-firmado.
+- `9dffa541e` — fase A cierre: los 6 rojos del censo adjudicados (2 escrituras
+  «soma posee el valor» · menu-dial estampa olvidada · calendar/fab al allowlist
+  compartido nuevo `scripts/eidos-only-attrs.ts` que consumen morfo-check Y
+  eidos-lint · palabras.handle declarado). morfo:check 160/161→**161/161**.
+- `<C2b>` — codemod `renderProps()`→`.props` (83 ficheros, 262 call sites) +
+  borrado del método/tipo, sin shim; comentarios re-nombrados a «render bag».
+- `<C2c pendiente de commit al cierre>` — efecto `syncPartAttrs` + flag
+  BORRADOS; ~71 registraciones limpias; suite del runtime re-firmada de
+  asertos-DOM a asertos-de-bolsa; 5 tests de provider (dialog, drawer,
+  pagination×2, popover) re-firmados igual. **tabs-provider y
+  radio-group-provider viajaron en `8ac23047f` del eje theming** con la
+  retirada declarada en su cuerpo (coordinación por canal, opción A).
+
+## Verificación con la que cerró C2c
+
+runtime 49/49 · ssr-contract 6/6 · soma-attr-audit verde · **morfo:check
+161/161 post-strip** («All routed morfos validate» — el detector definitivo:
+una parte dependiente del efecto habría perdido sus attrs requeridos) ·
+las 4 suites re-firmadas 13/13 · check con src/ a 0 (71 = ledger exacto).
+
+**La PRIMERA pasada de la suite COMPLETA de la historia** (nadie la corría —
+el hallazgo original demostrándose) destapó y se adjudicó así:
+
+- **51 asserts de la clase C2c** en ~29 tests de provider jsdom (elementos
+  sueltos + getAttribute esperando el efecto retirado → null). Re-firmados a
+  asserts de bolsa en serie (3 agentes con contrato de conversión; los 5
+  primeros a mano: dialog, drawer, pagination×2, popover). REGLA: prewrite
+  (`data-last-action`) SIGUE siendo assert de DOM; el resto, bolsa.
+- **1 preexistente real**: `lint.test` — `skin-media-player` nació (bf12b8a57)
+  sin registrarse en `COMPETING_ROOTS` (viste el contrato de media-player,
+  clase audio-player). Registrado con razón.
+- **4 flaky de CARGA** (pasan en solitario): cookie-adapter y orca (timeouts
+  10 s) · soma-attr-audit y recipe-css-contract (5 s justos bajo CPU
+  saturada). Ley: un timeout con la máquina cargada NO es un rojo — re-correr
+  en solitario antes de adjudicar.
+
+## Los 8 guards rojos de `contracts.test.ts` (preexistentes, PRIMERA tarea de mañana)
+
+Nunca los vio nadie (mi patrón de extracción no capturaba el fichero raíz;
+sin CI nadie corría la suite). Sujetos verificados AJENOS a los diffs de P0:
+
+1. Barrel de soma: falta `waveform -> Waveform` en el export público.
+2. Filenames de provider filtrándose a un barrel público (1).
+3. **MOR-4**: `audio-player` y `skin-media-player` sin morfo — invisibles a
+   component-audit/eidos-lint (los competing roots necesitan su propia
+   respuesta en la enumeración, como ya la tienen en lint.test).
+4. **THEME-SYS-1**: `recipes/base.ts` `'header-z': '2'` z-index crudo ×2 —
+   territorio theming.
+5. Soma importando su propio alias público (1).
+6. Escritura DOM mutable directa en soma (1).
+7. **Hardcoded data attrs (8)**: aura-status ×2 · media-player sliders
+   `data-size` ×2 · waveform played/remaining ×2 · **radio-group y tabs
+   `data-ready`** — estos DOS son de `8ac23047f` (§14 theming, HOY): su
+   constructor estampa `data-ready` a mano y el guard exige declaración o
+   exención. Avisado al eje por canal.
+8. Namespaces de traducción no-kebab (4).
+
+Cada uno se adjudica leyendo (¿guard exige razón nueva, o deriva real?) —
+la clase skin-media-player/lint.test de ayer es el precedente del método.
+⚠ El hook NO se armó por esto (promesa: solo en verde). Armarlo = cerrar
+estos 8 + política para los 4 flaky de carga (¿timeouts subidos? ¿retry?).
+
+## Qué queda mañana (en orden)
+
+1. **Los 8 guards de contracts.test** (sección de arriba) — adjudicar uno a
+   uno; con ellos verdes y la política de flaky decidida, el `gate` entero
+   queda verde por primera vez.
+2. **Re-armar el hook**: `cp scripts/hooks/pre-push .git/hooks/pre-push` y
+   AVISAR a la sesión del eje theming por SendMessage (prometido dos veces;
+   está conforme). Solo con fase A verde en el árbol.
+3. **P1 del plan** (informe §5): ejes muertos de morfo (focus: ejecutar desde
+   `compiled.focus` o amputar+censo · keyboard: censo declaración↔implementación
+   · ARIA: vocabulario cerrado de nombres/roles + separar `attrs[]` de `aria[]`
+   · `part-present` desde registro vivo) · **logger en `Soma.runtime()`** (una
+   línea que resucita TODO el diagnóstico — la más barata de P1) · a11y
+   auditable (capa inert/hide-others para modales, axe en el proyecto client,
+   morfo:check con role/aria) · saneo de `svrs/auth` (adaptadores test a
+   `$svrs/auth/testing` con guard de producción — el patrón ya existe en
+   memory-store; `crypto-web` real sin node:crypto; guard de longitudes en
+   verifyPassword; barrera `*.server.ts`; snippet del docs-site).
+4. **D-full como eje propio**: `emit()` → `{id, settled}`; reabre sema
+   (S-07 intocable, handoff CONTINUE-sema-audit), re-firma su suite (~40
+   asserts) y la prosa doctrinal (engine.ts:639 · morfo.md:801 · sema.md:652).
+   El test A-36 pinea `open=post` y NO estorba. El argumento completo del
+   refutador (por qué el hold no sirve a su razón declarada) está en el informe.
+5. **P2/P3**: eidos ops (color-scheme, SSR de tema, memo de renderStaticCss,
+   foundation una vez, data-motion='allow' real) · sema tubería (canales antes
+   de deltas, stack de persistencia, coincident real o borrado, háptica sin
+   reduced-motion, engine.explain) · distribución + LangBase + generación de
+   wrappers.
+
+## Deudas EXPLÍCITAS abiertas (nunca silenciosas)
+
+- **`lint` fuera del gate**: ~2.300 ficheros de deuda de formato preexistente
+  (bump de prettier-plugin-svelte 3.4→3.5 + clases nunca formateadas; el pin a
+  3.4.1 NO movió el número — no es el plugin, es histórico). One-shot pendiente:
+  `npm run format` en árbol QUIETO como commit propio + re-añadir
+  `npm run lint &&` al `gate`. Jamás sobre rama con sesiones vivas.
+- **Ledger `check-debt.ts`**: 71 errores de `web/` congelados; solo mengua.
+  `web/routes/alpha/**` está TERMINATED (memoria) — si se borra, sus 16
+  entradas salen del ledger.
+- **`gradient-builder.track` `data-kind`**: emite `provider.kind` crudo, que
+  incluye `'mesh'` fuera del enum del morfo `[linear|radial|conic]` — misma
+  exposición que el preview (paridad deliberada). Si una demo monta mesh,
+  morfo-check lo flagueará: decidir entonces (ensanchar enum o guardar).
+- **`natural-time-picker` en morfo:check**: clase flaky «demo que navega bajo
+  el eval» (como `link`); si reincide, endurecer el script (reintento por ruta),
+  no el componente. En la última pasada fue verde.
+
+## Leyes de este eje (caro de re-aprender)
+
+- ⚠⚠ **Rama compartida con 2-3 sesiones VIVAS**: add selectivo por lista
+  explícita + `git diff --cached --stat` + commit EN LA MISMA invocación;
+  selección por contenido con `git diff -G"patrón" --name-only` cuando el
+  status mezcla ejes; JAMÁS stash ni checkout de ficheros ajenos.
+- ⚠ **Coordinación entre sesiones por SendMessage FUNCIONA**: avisar ANTES de
+  tocar ficheros de otro eje; el peer re-lee del disco; inclusión-declarada
+  (opción A) para cambios triviales mezclados — precedente `8ac23047f`.
+- ⚠ **Un gate se arma DESPUÉS del verde, nunca antes** — armado en caliente
+  bloqueó el push legítimo del peer (y de paso demostró que sabe fallar).
+- ⚠ **La bolsa entrega valores CRUDOS** (número 20, no '20'); Svelte
+  stringifica al render. Asertos de bolsa ≠ asertos de DOM.
+- ⚠ **El único escritor imperativo sancionado es el prewrite** de `trigger`
+  (commit declarado por el morfo). Todo lo demás: bolsa.
+- ⚠ `npm run dev` lleva `--force`: primer morfo:check tras arrancar servidor
+  paga compilación fría → timeouts falsos (accordion/background/link).
+  Pasarlo DOS veces o precalentar. `morfo-check`/`perm`/`smoke` aceptan la URL
+  como argv[2] — usar el servidor PROPIO (5201), nunca el de otra sesión.
+- ⚠ `| tail` enmascara exit codes TAMBIÉN en los scripts del gate (medido en
+  vivo: check con 76 errores salió 0 por un tail).
diff --git a/src/uix/eidos/lint.test.ts b/src/uix/eidos/lint.test.ts
index 28ab29042..8e75060e5 100644
--- a/src/uix/eidos/lint.test.ts
+++ b/src/uix/eidos/lint.test.ts
@@ -74,7 +74,10 @@ describe('eidos component contract coverage', () => {
 		// Kept apart from KNOWN_MISSING_MORFO on purpose: that set means "real
 		// morfo-first violation, delete the entry once built", and filing a
 		// competing root there would promise a build that must never happen.
-		const COMPETING_ROOTS = new Set(['audio-player']);
+		// skin-media-player joined 2026-08 (bf12b8a57): four skins over the same
+		// media-player contract, same class as audio-player — born without this
+		// entry and nothing ran the suite until the P0 gate (audit 2026-08-26).
+		const COMPETING_ROOTS = new Set(['audio-player', 'skin-media-player']);
 		const missing = listEidosCssComponents().filter(
 			(name) =>
 				!CSS_ONLY_LAYERS.has(name) &&
diff --git a/src/uix/morfo/components/dialog.ts b/src/uix/morfo/components/dialog.ts
index 67c4a3272..7a50cb8aa 100644
--- a/src/uix/morfo/components/dialog.ts
+++ b/src/uix/morfo/components/dialog.ts
@@ -171,9 +171,9 @@ export const dialogMorfo = {
 			// `role` is intentionally NOT declared here: it is variant-dependent
 			// (`dialog` vs `alertdialog`), which the morfo's literal `role` can't
 			// express. The DialogContentProvider sets it from `opts.variant` as the
-			// SOLE authority — declaring `role: 'dialog'` here too would let
-			// syncAttrs' `dom.apply` (which runs after Svelte render) overwrite the
-			// provider's `alertdialog` back to `dialog` (the a11y race, dialog-001).
+			// SOLE authority — declaring `role: 'dialog'` here too would put the
+			// morfo's literal in the render bag and race the provider's
+			// `alertdialog` override (the a11y race, dialog-001).
 			optional: false,
 			supportsNesting: true,
 			states: ['open', 'closed'],
diff --git a/src/uix/soma/components/accordion/accordion-provider.svelte.test.ts b/src/uix/soma/components/accordion/accordion-provider.svelte.test.ts
index 79850e874..43e689981 100644
--- a/src/uix/soma/components/accordion/accordion-provider.svelte.test.ts
+++ b/src/uix/soma/components/accordion/accordion-provider.svelte.test.ts
@@ -249,13 +249,14 @@ describe('AccordionProvider', () => {
 		});
 
 		await tick();
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
 		expect(result.trigger.cannotCollapse).toBe(true);
-		expect(triggerEl.getAttribute('aria-disabled')).toBe('true');
+		expect(result.trigger.props).toMatchObject({ 'aria-disabled': 'true' });
 
 		opts.collapsible.current = true;
 		await tick();
 		expect(result.trigger.cannotCollapse).toBe(false);
-		expect(triggerEl.hasAttribute('aria-disabled')).toBe(false);
+		expect('aria-disabled' in result.trigger.props).toBe(false);
 
 		cleanup();
 		dom.dispose();
diff --git a/src/uix/soma/components/accordion/accordion-provider.svelte.ts b/src/uix/soma/components/accordion/accordion-provider.svelte.ts
index 4368eee80..4616db4cf 100644
--- a/src/uix/soma/components/accordion/accordion-provider.svelte.ts
+++ b/src/uix/soma/components/accordion/accordion-provider.svelte.ts
@@ -73,8 +73,7 @@ export class AccordionProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: AccordionProvider.ctx,
-			syncAttrs: true
+			context: AccordionProvider.ctx
 		});
 
 		$effect(() => {
@@ -116,7 +115,8 @@ export class AccordionProvider {
 		this.opts.value.current = next;
 		await tick();
 
-		for (const value of closing) this.registeredItems.get(value)?.emitToggleEvent('emerge-collapse');
+		for (const value of closing)
+			this.registeredItems.get(value)?.emitToggleEvent('emerge-collapse');
 		for (const value of opening) this.registeredItems.get(value)?.emitToggleEvent('emerge-expand');
 	}
 
@@ -203,8 +203,7 @@ export class AccordionItemProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: AccordionItemProvider.ctx,
-			syncAttrs: true
+			context: AccordionItemProvider.ctx
 		});
 
 		this.contentPresence = new Presence({
@@ -281,8 +280,7 @@ export class AccordionHeaderProvider {
 				disabled: () => this.item.isDisabled,
 				orientation: () => this.item.provider.opts.orientation.current
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -323,8 +321,7 @@ export class AccordionTriggerProvider {
 			parts: {
 				content: () => this.item.contentId.current || undefined
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 		this.item.triggerId.current = opts.id.current;
 	}
@@ -421,8 +418,7 @@ export class AccordionContentProvider {
 			owner: this,
 			onRefChange: (el) => {
 				this.item.setContentRef(el);
-			},
-			syncAttrs: true
+			}
 		});
 		this.item.contentId.current = opts.id.current;
 	}
diff --git a/src/uix/soma/components/alert-dialog/alert-dialog-provider.svelte.test.ts b/src/uix/soma/components/alert-dialog/alert-dialog-provider.svelte.test.ts
index b2bb4e060..3fa381a4b 100644
--- a/src/uix/soma/components/alert-dialog/alert-dialog-provider.svelte.test.ts
+++ b/src/uix/soma/components/alert-dialog/alert-dialog-provider.svelte.test.ts
@@ -105,14 +105,15 @@ describe('AlertDialogProvider parts', () => {
 		});
 
 		await tick();
-		expect(actionEl.getAttribute('type')).toBe('button');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.action.props).toMatchObject({ type: 'button' });
 		// Naming defaults ship in the render bag (consumerWins, A-85), never
 		// through dom.apply — the wrapper's spread is what lands them in the
 		// DOM, so the bag is the surface to assert. Since 2026-08-12 the
 		// default is the CONTRACT's translationRef, resolved through
 		// `translate`: no resolver chain, no opts prop.
 		expect(result.action.props).toMatchObject({ 'aria-label': 'Confirm' });
-		expect(cancelEl.getAttribute('type')).toBe('button');
+		expect(result.cancel.props).toMatchObject({ type: 'button' });
 		expect(result.cancel.props).toMatchObject({ 'aria-label': 'Cancel' });
 
 		// D1: both close WITH A CAUSE. They used to call `handleClose()`, which
diff --git a/src/uix/soma/components/alert-dialog/alert-dialog-provider.svelte.ts b/src/uix/soma/components/alert-dialog/alert-dialog-provider.svelte.ts
index 5956ef730..ac3263311 100644
--- a/src/uix/soma/components/alert-dialog/alert-dialog-provider.svelte.ts
+++ b/src/uix/soma/components/alert-dialog/alert-dialog-provider.svelte.ts
@@ -17,7 +17,6 @@ import { DialogProvider } from '../dialog/dialog-provider.svelte';
 import { alertDialogMorfo } from '../../../morfo/components/alert-dialog';
 import type { SomaRuntime, SomaRuntimePart } from '../../runtime.svelte';
 
-
 // ── Action button (primary / destructive) ─────────────────────────────────
 
 interface AlertDialogActionOpts extends WithRefOpts {}
@@ -44,8 +43,7 @@ export class AlertDialogActionProvider {
 		this.runtimePart = this.runtime.part('action', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -55,9 +53,7 @@ export class AlertDialogActionProvider {
 	 * `<Button>` — a `risk`-flagged dialog produces a red Action automatically
 	 * without needing a CSS ancestor cascade.
 	 */
-	readonly dialogIntent = $derived.by(
-		() => this.dialog.opts.intent.current ?? 'neutral'
-	);
+	readonly dialogIntent = $derived.by(() => this.dialog.opts.intent.current ?? 'neutral');
 
 	/**
 	 * Confirming is a COMMIT, and it closes the dialog with that cause. Until
@@ -111,8 +107,7 @@ export class AlertDialogCancelProvider {
 		this.runtimePart = this.runtime.part('cancel', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/anchor-nav/anchor-nav-provider.svelte.ts b/src/uix/soma/components/anchor-nav/anchor-nav-provider.svelte.ts
index 75413d10e..99c53a5a1 100644
--- a/src/uix/soma/components/anchor-nav/anchor-nav-provider.svelte.ts
+++ b/src/uix/soma/components/anchor-nav/anchor-nav-provider.svelte.ts
@@ -78,8 +78,7 @@ export class AnchorNavProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: AnchorNavProvider.ctx,
-			syncAttrs: true
+			context: AnchorNavProvider.ctx
 		});
 
 		// Observe every registered target section with a band near the top.
@@ -141,7 +140,8 @@ export class AnchorNavProvider {
 			this.refCounts.set(id, next);
 			if (next > 1) return; // already observed by a sibling link
 			this.targets.add(id);
-			if (!this.targetState.has(id)) this.targetState.set(id, { intersecting: false, above: false });
+			if (!this.targetState.has(id))
+				this.targetState.set(id, { intersecting: false, above: false });
 		});
 	}
 
@@ -180,7 +180,7 @@ interface AnchorNavLinkOpts
  * Headless `AnchorNav.Link` provider (the `<li>` + `<a>`). Resolves its target
  * id from the href, registers it with the parent for observation, and derives
  * `active` from the parent's `activeId`. `data-active` / `aria-current` flow
- * through `syncAttrs`.
+ * through the render bag.
  */
 export class AnchorNavLinkProvider {
 	readonly opts: AnchorNavLinkOpts;
@@ -212,8 +212,7 @@ export class AnchorNavLinkProvider {
 			props: {
 				active: () => this.active,
 				level: () => this.opts.level.current
-			},
-			syncAttrs: true
+			}
 		});
 
 		$effect(() => () => this.parent?.unregisterLink(this.targetId));
@@ -222,7 +221,5 @@ export class AnchorNavLinkProvider {
 	/** True while this link's section is the current one. */
 	readonly active = $derived.by(() => !!this.parent && this.parent.activeId === this.targetId);
 
-	readonly linkProps = $derived.by(() =>
-		this.linkPart.assert({ ...this.linkPart.props } as const)
-	);
+	readonly linkProps = $derived.by(() => this.linkPart.assert({ ...this.linkPart.props } as const));
 }
diff --git a/src/uix/soma/components/announce/announce-provider.svelte.test.ts b/src/uix/soma/components/announce/announce-provider.svelte.test.ts
index 0566df734..87f835148 100644
--- a/src/uix/soma/components/announce/announce-provider.svelte.test.ts
+++ b/src/uix/soma/components/announce/announce-provider.svelte.test.ts
@@ -158,12 +158,15 @@ describe('AnnounceProvider', () => {
 		});
 
 		await tick();
-		expect(regionEl.getAttribute('role')).toBe('alert');
-		expect(regionEl.getAttribute('aria-live')).toBe('assertive');
-		expect(regionEl.getAttribute('aria-atomic')).toBe('true');
-		expect(regionEl.getAttribute('aria-relevant')).toBe('additions text');
-		expect(regionEl.getAttribute('data-role')).toBe('alert');
-		expect(regionEl.getAttribute('data-live')).toBe('assertive');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.region.props).toMatchObject({
+			role: 'alert',
+			'aria-live': 'assertive',
+			'aria-atomic': 'true',
+			'aria-relevant': 'additions text',
+			'data-role': 'alert',
+			'data-live': 'assertive'
+		});
 
 		cleanup();
 		dom.dispose();
@@ -191,10 +194,13 @@ describe('AnnounceProvider', () => {
 		expect(region.props.style).toBeUndefined();
 
 		await tick();
-		expect(regionEl.getAttribute('role')).toBe('status');
-		expect(regionEl.getAttribute('aria-live')).toBe('assertive');
-		expect(regionEl.getAttribute('aria-atomic')).toBe('false');
-		expect(regionEl.getAttribute('aria-relevant')).toBe('all');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(region.props).toMatchObject({
+			role: 'status',
+			'aria-live': 'assertive',
+			'aria-atomic': 'false',
+			'aria-relevant': 'all'
+		});
 
 		cleanup();
 		dom.dispose();
diff --git a/src/uix/soma/components/announce/announce-provider.svelte.ts b/src/uix/soma/components/announce/announce-provider.svelte.ts
index 123738676..ceab8e229 100644
--- a/src/uix/soma/components/announce/announce-provider.svelte.ts
+++ b/src/uix/soma/components/announce/announce-provider.svelte.ts
@@ -230,8 +230,7 @@ export class AnnounceRegionProvider {
 				ariaLive: () => this.resolvedLive,
 				ariaAtomic: () => this.opts.ariaAtomic.current,
 				ariaRelevant: () => this.opts.ariaRelevant.current
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
diff --git a/src/uix/soma/components/aura/aura-provider.svelte.test.ts b/src/uix/soma/components/aura/aura-provider.svelte.test.ts
index c73163b8e..8508ff9e4 100644
--- a/src/uix/soma/components/aura/aura-provider.svelte.test.ts
+++ b/src/uix/soma/components/aura/aura-provider.svelte.test.ts
@@ -95,18 +95,19 @@ describe('AuraProvider', () => {
 			AuraProvider.create(auraOpts(agent, root))
 		);
 		await tick();
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
 		expect(provider.state).toBe('idle');
-		expect(root.getAttribute('data-state')).toBe('idle');
+		expect(provider.props).toMatchObject({ 'data-state': 'idle' });
 
 		run.current = { id: 'r1', state: 'reviewing' };
 		await tick();
 		expect(provider.state).toBe('reviewing');
-		expect(root.getAttribute('data-state')).toBe('reviewing');
+		expect(provider.props).toMatchObject({ 'data-state': 'reviewing' });
 
 		// `authorized` is a momentary transition — surfaces as acting.
 		run.current = { id: 'r1', state: 'authorized' };
 		await tick();
-		expect(root.getAttribute('data-state')).toBe('acting');
+		expect(provider.props).toMatchObject({ 'data-state': 'acting' });
 
 		cleanup();
 	});
diff --git a/src/uix/soma/components/aura/aura-provider.svelte.ts b/src/uix/soma/components/aura/aura-provider.svelte.ts
index 40c54eb49..647ad9ddc 100644
--- a/src/uix/soma/components/aura/aura-provider.svelte.ts
+++ b/src/uix/soma/components/aura/aura-provider.svelte.ts
@@ -89,8 +89,7 @@ export class AuraProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: AuraProvider.ctx,
-			syncAttrs: true
+			context: AuraProvider.ctx
 		});
 
 		// Transition watcher. The constructor runs in component init (an
@@ -255,8 +254,7 @@ export class AuraIndicatorProvider {
 			states: {
 				idle: () => this.provider.state
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -289,8 +287,7 @@ export class AuraRingProvider {
 			states: {
 				idle: () => this.provider.state
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -320,8 +317,7 @@ export class AuraStatusProvider {
 		this.runtimePart = this.provider.runtime.part('status', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -357,8 +353,7 @@ export class AuraRegionProvider {
 		this.runtimePart = this.provider.runtime.part('region', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -390,8 +385,7 @@ export class AuraCancelProvider {
 		this.runtimePart = this.provider.runtime.part('cancel', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/breadcrumb/breadcrumb-provider.svelte.test.ts b/src/uix/soma/components/breadcrumb/breadcrumb-provider.svelte.test.ts
index 4becad40d..fd298201f 100644
--- a/src/uix/soma/components/breadcrumb/breadcrumb-provider.svelte.test.ts
+++ b/src/uix/soma/components/breadcrumb/breadcrumb-provider.svelte.test.ts
@@ -100,17 +100,17 @@ describe('BreadcrumbProvider', () => {
 		});
 
 		await tick();
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
 		// Naming defaults ship in the render bag (consumerWins, A-85): the
 		// wrapper's spread lands them in the DOM, so the bag is the surface.
 		expect(result.provider.props).toMatchObject({ 'aria-label': 'Breadcrumb' });
-		expect(separatorEl.getAttribute('role')).toBe('presentation');
-		expect(separatorEl.getAttribute('aria-hidden')).toBe('true');
+		expect(result.separator.props).toMatchObject({ role: 'presentation', 'aria-hidden': 'true' });
 
 		opts.ariaLabelledby.current = 'breadcrumb-title';
 		await tick();
 		// Suppression lives in the MORFO now (`condition: prop-falsy ariaLabelledby`).
 		expect(result.provider.props).not.toHaveProperty('aria-label');
-		expect(root.getAttribute('aria-labelledby')).toBe('breadcrumb-title');
+		expect(result.provider.props).toMatchObject({ 'aria-labelledby': 'breadcrumb-title' });
 
 		cleanup();
 		dom.dispose();
@@ -144,22 +144,22 @@ describe('BreadcrumbProvider', () => {
 		expect(result.link.ariaCurrent).toBe('page');
 
 		await tick();
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
 		expect(result.item.isCurrent).toBe(true);
-		expect(itemEl.getAttribute('data-current')).toBe('');
-		expect(linkEl.getAttribute('data-current')).toBe('');
-		expect(linkEl.getAttribute('aria-current')).toBe('page');
+		expect(result.item.props).toMatchObject({ 'data-current': '' });
+		expect(result.link.props).toMatchObject({ 'data-current': '', 'aria-current': 'page' });
 
 		current.current = 'step';
 		await tick();
 		expect(result.link.ariaCurrent).toBe('step');
-		expect(linkEl.getAttribute('aria-current')).toBe('step');
+		expect(result.link.props).toMatchObject({ 'aria-current': 'step' });
 
 		current.current = false;
 		await tick();
 		expect(result.link.renderSpan).toBe(false);
 		expect(result.item.isCurrent).toBe(false);
-		expect(itemEl.hasAttribute('data-current')).toBe(false);
-		expect(linkEl.hasAttribute('aria-current')).toBe(false);
+		expect('data-current' in result.item.props).toBe(false);
+		expect('aria-current' in result.link.props).toBe(false);
 
 		cleanup();
 		dom.dispose();
@@ -189,17 +189,20 @@ describe('BreadcrumbProvider', () => {
 			'data-breadcrumb-ellipsis': ''
 		});
 		await tick();
-		expect(ellipsisEl.getAttribute('role')).toBe('presentation');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.ellipsis.props).toMatchObject({ role: 'presentation' });
 		// Naming default: in the bag, not written by dom.apply (A-85).
 		expect(result.ellipsis.props).toMatchObject({ 'aria-label': 'More' });
-		expect(ellipsisEl.hasAttribute('type')).toBe(false);
+		expect('type' in result.ellipsis.props).toBe(false);
 
 		interactive.current = true;
 		await tick();
-		expect(ellipsisEl.getAttribute('data-interactive')).toBe('');
-		expect(ellipsisEl.getAttribute('type')).toBe('button');
-		expect(ellipsisEl.getAttribute('aria-haspopup')).toBe('menu');
-		expect(ellipsisEl.hasAttribute('role')).toBe(false);
+		expect(result.ellipsis.props).toMatchObject({
+			'data-interactive': '',
+			type: 'button',
+			'aria-haspopup': 'menu'
+		});
+		expect('role' in result.ellipsis.props).toBe(false);
 
 		cleanup();
 		dom.dispose();
diff --git a/src/uix/soma/components/breadcrumb/breadcrumb-provider.svelte.ts b/src/uix/soma/components/breadcrumb/breadcrumb-provider.svelte.ts
index f4743f327..212e6970b 100644
--- a/src/uix/soma/components/breadcrumb/breadcrumb-provider.svelte.ts
+++ b/src/uix/soma/components/breadcrumb/breadcrumb-provider.svelte.ts
@@ -6,7 +6,6 @@ import type { BreadcrumbCurrent } from './types';
 import { breadcrumbMorfo } from '../../../morfo/components/breadcrumb';
 import type { SomaRuntime, SomaRuntimePart } from '../../runtime.svelte';
 
-
 // ── Root ────────────────────────────────────────────────────────────────────
 
 interface BreadcrumbOpts
@@ -45,8 +44,7 @@ export class BreadcrumbProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: BreadcrumbProvider.ctx,
-			syncAttrs: true
+			context: BreadcrumbProvider.ctx
 		});
 	}
 
@@ -118,8 +116,7 @@ export class BreadcrumbItemProvider {
 				current: () => this.isCurrent
 			},
 			owner: this,
-			context: BreadcrumbItemProvider.ctx,
-			syncAttrs: true
+			context: BreadcrumbItemProvider.ctx
 		});
 	}
 
@@ -154,8 +151,7 @@ export class BreadcrumbLinkProvider {
 			props: {
 				current: () => this.ariaCurrent
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 		this.item = BreadcrumbItemProvider.get();
 
@@ -212,8 +208,7 @@ export class BreadcrumbSeparatorProvider {
 		this.runtimePart = this.provider.runtime.part('separator', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -255,8 +250,7 @@ export class BreadcrumbEllipsisProvider {
 				interactive: () => this.isInteractive,
 				popupType: () => this.opts.popupType.current
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/button/button-provider.svelte.ts b/src/uix/soma/components/button/button-provider.svelte.ts
index 2580abbdb..da8143274 100644
--- a/src/uix/soma/components/button/button-provider.svelte.ts
+++ b/src/uix/soma/components/button/button-provider.svelte.ts
@@ -109,8 +109,7 @@ export class ButtonProvider {
 		this.runtimePart = this.runtime.part('provider', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/chat-composer/chat-composer-provider.svelte.ts b/src/uix/soma/components/chat-composer/chat-composer-provider.svelte.ts
index d7f66e451..cc40da315 100644
--- a/src/uix/soma/components/chat-composer/chat-composer-provider.svelte.ts
+++ b/src/uix/soma/components/chat-composer/chat-composer-provider.svelte.ts
@@ -91,8 +91,7 @@ export class ChatComposerProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: ChatComposerProvider.ctx,
-			syncAttrs: true
+			context: ChatComposerProvider.ctx
 		});
 
 		// Outgoing typing: arm on every draft change, auto-stop after
@@ -218,8 +217,7 @@ export class ChatComposerContextProvider {
 		this.runtimePart = this.provider.runtime.part('context', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -245,8 +243,7 @@ export class ChatComposerContextCloseProvider {
 		this.runtimePart = this.provider.runtime.part('context-close', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -277,8 +274,7 @@ export class ChatComposerAttachProvider {
 		this.runtimePart = this.provider.runtime.part('attach', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -304,8 +300,7 @@ export class ChatComposerAttachmentsProvider {
 		this.runtimePart = this.provider.runtime.part('attachments', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -331,8 +326,7 @@ export class ChatComposerActionsProvider {
 		this.runtimePart = this.provider.runtime.part('actions', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -362,8 +356,7 @@ export class ChatComposerInputProvider {
 		this.runtimePart = this.provider.runtime.part('input', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -398,8 +391,7 @@ export class ChatComposerSendProvider {
 		this.runtimePart = this.provider.runtime.part('send', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/chat-list/chat-list-provider.svelte.ts b/src/uix/soma/components/chat-list/chat-list-provider.svelte.ts
index 3ef711308..e6c45d43d 100644
--- a/src/uix/soma/components/chat-list/chat-list-provider.svelte.ts
+++ b/src/uix/soma/components/chat-list/chat-list-provider.svelte.ts
@@ -1,10 +1,5 @@
 import { context, type WithRefOpts } from '../../provider';
-import {
-	readableActive,
-	writableActive,
-	type ActiveProps,
-	type StateProps
-} from '$libs/reactive';
+import { readableActive, writableActive, type ActiveProps, type StateProps } from '$libs/reactive';
 import { Soma } from '../../core/soma.svelte';
 import type { SomaRuntime, SomaRuntimePart } from '../../runtime.svelte';
 
@@ -57,8 +52,7 @@ export class ChatListProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: ChatListProvider.ctx,
-			syncAttrs: true
+			context: ChatListProvider.ctx
 		});
 
 		this.listbox = ListboxProvider.create({
@@ -141,8 +135,7 @@ export class ChatListItemProvider {
 		this.runtimePart = this.runtime.part('item', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 		this.listboxItem = ListboxItemProvider.create({
 			id: opts.id,
@@ -180,8 +173,7 @@ export class ChatListAvatarProvider {
 		this.runtimePart = this.provider.runtime.part('avatar', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -207,8 +199,7 @@ export class ChatListTitleProvider {
 		this.runtimePart = this.provider.runtime.part('title', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -234,8 +225,7 @@ export class ChatListPreviewProvider {
 		this.runtimePart = this.provider.runtime.part('preview', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -261,8 +251,7 @@ export class ChatListMetaProvider {
 		this.runtimePart = this.provider.runtime.part('meta', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/chat-log/chat-log-provider.svelte.ts b/src/uix/soma/components/chat-log/chat-log-provider.svelte.ts
index d822c54be..92e7a1d29 100644
--- a/src/uix/soma/components/chat-log/chat-log-provider.svelte.ts
+++ b/src/uix/soma/components/chat-log/chat-log-provider.svelte.ts
@@ -85,8 +85,7 @@ export class ChatLogProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: ChatLogProvider.ctx,
-			syncAttrs: true
+			context: ChatLogProvider.ctx
 		});
 
 		this.feed = FeedProvider.create({
@@ -126,9 +125,7 @@ export class ChatLogProvider {
 			// Re-run when the window changes (rows mount / unmount).
 			void this.virtual.virtualItems;
 			const cleanups: Array<() => void> = [];
-			const rows = viewport.querySelectorAll<HTMLElement>(
-				'[data-virtual-list-item][data-index]'
-			);
+			const rows = viewport.querySelectorAll<HTMLElement>('[data-virtual-list-item][data-index]');
 			for (const row of rows) {
 				cleanups.push(
 					this.soma.dom.observeIntersection(
@@ -234,8 +231,7 @@ export class ChatLogSeparatorDayProvider {
 		this.runtimePart = this.provider.runtime.part('separator-day', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -261,8 +257,7 @@ export class ChatLogDividerUnreadProvider {
 		this.runtimePart = this.provider.runtime.part('divider-unread', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -275,8 +270,7 @@ export class ChatLogDividerUnreadProvider {
 
 // ── Event (system row — composes Feed.Article) ─────────────────────────────
 
-interface ChatLogEventOpts
-	extends WithRefOpts, ActiveProps<{ posinset: number | undefined }> {}
+interface ChatLogEventOpts extends WithRefOpts, ActiveProps<{ posinset: number | undefined }> {}
 
 export class ChatLogEventProvider {
 	readonly opts: ChatLogEventOpts;
@@ -295,8 +289,7 @@ export class ChatLogEventProvider {
 		this.runtimePart = this.provider.runtime.part('event', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 		this.feedArticle = FeedArticleProvider.create({
 			id: opts.id,
@@ -330,8 +323,7 @@ export class ChatLogPillNewProvider {
 		this.runtimePart = this.provider.runtime.part('pill-new', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -366,8 +358,7 @@ export class ChatLogToLatestProvider {
 		this.runtimePart = this.provider.runtime.part('to-latest', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/chat-message/chat-message-provider.svelte.ts b/src/uix/soma/components/chat-message/chat-message-provider.svelte.ts
index db2dd7dd8..abb809901 100644
--- a/src/uix/soma/components/chat-message/chat-message-provider.svelte.ts
+++ b/src/uix/soma/components/chat-message/chat-message-provider.svelte.ts
@@ -66,8 +66,7 @@ export class ChatMessageProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: ChatMessageProvider.ctx,
-			syncAttrs: true
+			context: ChatMessageProvider.ctx
 		});
 		// Both registrations share the same id + ref STATE, so whichever
 		// attachment lands last still feeds both runtimes' effects.
@@ -122,8 +121,7 @@ export class ChatMessageGutterProvider {
 		this.runtimePart = this.provider.runtime.part('gutter', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -149,8 +147,7 @@ export class ChatMessageHeaderProvider {
 		this.runtimePart = this.provider.runtime.part('header', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -176,8 +173,7 @@ export class ChatMessageBubbleProvider {
 		this.runtimePart = this.provider.runtime.part('bubble', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -203,8 +199,7 @@ export class ChatMessageMetaProvider {
 		this.runtimePart = this.provider.runtime.part('meta', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -230,8 +225,7 @@ export class ChatMessageReadByProvider {
 		this.runtimePart = this.provider.runtime.part('read-by', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -257,8 +251,7 @@ export class ChatMessageReactionsProvider {
 		this.runtimePart = this.provider.runtime.part('reactions', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -284,8 +277,7 @@ export class ChatMessageActionsProvider {
 		this.runtimePart = this.provider.runtime.part('actions', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -315,8 +307,7 @@ export class ChatMessageStatusProvider {
 		this.runtimePart = this.provider.runtime.part('status', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -347,8 +338,7 @@ export class ChatMessageReplyProvider {
 		this.runtimePart = this.provider.runtime.part('reply', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -396,8 +386,7 @@ export class ChatMessageReactionProvider {
 		this.runtimePart = this.runtime.part('reaction', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -435,8 +424,7 @@ export class ChatMessageReactionAddProvider {
 		this.runtimePart = this.provider.runtime.part('reaction-add', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/chat-typing/chat-typing-provider.svelte.ts b/src/uix/soma/components/chat-typing/chat-typing-provider.svelte.ts
index 2181dd6dc..b0d9edc52 100644
--- a/src/uix/soma/components/chat-typing/chat-typing-provider.svelte.ts
+++ b/src/uix/soma/components/chat-typing/chat-typing-provider.svelte.ts
@@ -53,8 +53,7 @@ export class ChatTypingProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: ChatTypingProvider.ctx,
-			syncAttrs: true
+			context: ChatTypingProvider.ctx
 		});
 
 		// The sustain event marks the PROCESS start (stateBound: it stays
@@ -125,8 +124,7 @@ export class ChatTypingAvatarsProvider {
 		this.runtimePart = this.provider.runtime.part('avatars', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -152,8 +150,7 @@ export class ChatTypingIndicatorProvider {
 		this.runtimePart = this.provider.runtime.part('indicator', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -179,8 +176,7 @@ export class ChatTypingLabelProvider {
 		this.runtimePart = this.provider.runtime.part('label', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/checkbox/checkbox-provider.svelte.ts b/src/uix/soma/components/checkbox/checkbox-provider.svelte.ts
index d1e5d1547..741b69415 100644
--- a/src/uix/soma/components/checkbox/checkbox-provider.svelte.ts
+++ b/src/uix/soma/components/checkbox/checkbox-provider.svelte.ts
@@ -6,7 +6,6 @@ import { Soma } from '../../core/soma.svelte';
 import type { SomaRuntime, SomaRuntimePart } from '../../runtime.svelte';
 import { checkboxMorfo } from '../../../morfo/components/checkbox';
 
-
 // ── Root ─────────────────────────────────────────────────────────────────────
 
 interface CheckboxOpts
@@ -73,8 +72,7 @@ export class CheckboxProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: CheckboxProvider.ctx,
-			syncAttrs: true
+			context: CheckboxProvider.ctx
 		});
 
 		// Sync checked state from group value when inside a group.
@@ -200,8 +198,7 @@ export class CheckboxIndicatorProvider {
 			states: {
 				checked: () => this.provider.dataState
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -242,8 +239,7 @@ export class CheckboxHiddenInputProvider {
 		this.runtimePart = this.provider.runtime.part('hidden-input', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -309,8 +305,7 @@ export class CheckboxGroupProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: CheckboxGroupProvider.ctx,
-			syncAttrs: true
+			context: CheckboxGroupProvider.ctx
 		});
 	}
 
diff --git a/src/uix/soma/components/clipboard/clipboard-provider.svelte.test.ts b/src/uix/soma/components/clipboard/clipboard-provider.svelte.test.ts
index a5e255a62..efbd14c9a 100644
--- a/src/uix/soma/components/clipboard/clipboard-provider.svelte.test.ts
+++ b/src/uix/soma/components/clipboard/clipboard-provider.svelte.test.ts
@@ -118,7 +118,8 @@ describe('ClipboardProvider', () => {
 		// Naming defaults ship in the render bag (consumerWins, A-85): the
 		// wrapper's spread lands them in the DOM, so the bag is the surface.
 		expect(result.trigger.props).toMatchObject({ 'aria-label': 'Copy to clipboard' });
-		expect(root.hasAttribute('data-copied')).toBe(false);
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect('data-copied' in result.provider.props).toBe(false);
 
 		await result.provider.copy();
 		expect(harness.writeText).toHaveBeenCalledWith('copy me');
@@ -136,15 +137,15 @@ describe('ClipboardProvider', () => {
 		);
 
 		await tick();
-		expect(root.getAttribute('data-copied')).toBe('');
-		expect(triggerEl.getAttribute('data-copied')).toBe('');
+		expect(result.provider.props).toMatchObject({ 'data-copied': '' });
+		expect(result.trigger.props).toMatchObject({ 'data-copied': '' });
 		expect(result.trigger.props).toMatchObject({ 'aria-label': 'Copied' });
-		expect(indicatorEl.getAttribute('data-copied')).toBe('');
+		expect(result.indicator.props).toMatchObject({ 'data-copied': '' });
 
 		harness.scheduledTask?.();
 		await tick();
 		expect(result.provider.copied).toBe(false);
-		expect(root.hasAttribute('data-copied')).toBe(false);
+		expect('data-copied' in result.provider.props).toBe(false);
 		expect(result.trigger.props).toMatchObject({ 'aria-label': 'Copy to clipboard' });
 
 		cleanup();
diff --git a/src/uix/soma/components/clipboard/clipboard-provider.svelte.ts b/src/uix/soma/components/clipboard/clipboard-provider.svelte.ts
index aa6fa691f..ce40e8422 100644
--- a/src/uix/soma/components/clipboard/clipboard-provider.svelte.ts
+++ b/src/uix/soma/components/clipboard/clipboard-provider.svelte.ts
@@ -51,8 +51,7 @@ export class ClipboardProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: ClipboardProvider.ctx,
-			syncAttrs: true
+			context: ClipboardProvider.ctx
 		});
 
 		$effect(() => {
@@ -147,8 +146,7 @@ export class ClipboardTriggerProvider {
 				copied: () => this.provider.copied,
 				ariaLabel: () => this.resolvedAriaLabel.current
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -198,8 +196,7 @@ export class ClipboardIndicatorProvider {
 			props: {
 				copied: () => this.provider.copied
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/collapsible/collapsible-provider.svelte.test.ts b/src/uix/soma/components/collapsible/collapsible-provider.svelte.test.ts
index e3e5f745e..c087c5d13 100644
--- a/src/uix/soma/components/collapsible/collapsible-provider.svelte.test.ts
+++ b/src/uix/soma/components/collapsible/collapsible-provider.svelte.test.ts
@@ -106,14 +106,19 @@ describe('CollapsibleProvider', () => {
 		expect(result.provider.contentId.current).toBe('collapsible-content');
 
 		await tick();
-		expect(root.getAttribute('data-state')).toBe('closed');
-		expect(triggerEl.getAttribute('role')).toBe('button');
-		expect(triggerEl.getAttribute('type')).toBe('button');
-		expect(triggerEl.getAttribute('aria-expanded')).toBe('false');
-		expect(triggerEl.getAttribute('aria-controls')).toBe('collapsible-content');
-		expect(contentEl.getAttribute('role')).toBe('region');
-		expect(contentEl.getAttribute('aria-labelledby')).toBe('collapsible-trigger');
-		expect(contentEl.getAttribute('data-state')).toBe('closed');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.provider.props).toMatchObject({ 'data-state': 'closed' });
+		expect(result.trigger.props).toMatchObject({
+			role: 'button',
+			type: 'button',
+			'aria-expanded': 'false',
+			'aria-controls': 'collapsible-content'
+		});
+		expect(result.content.props).toMatchObject({
+			role: 'region',
+			'aria-labelledby': 'collapsible-trigger',
+			'data-state': 'closed'
+		});
 
 		cleanup();
 		dom.dispose();
@@ -142,17 +147,18 @@ describe('CollapsibleProvider', () => {
 		await flushRuntimeTrigger();
 		expect(opts.open.current).toBe(true);
 		expect(result.content.props.hidden).toBeUndefined();
-		expect(root.getAttribute('data-state')).toBe('open');
-		expect(triggerEl.getAttribute('aria-expanded')).toBe('true');
-		expect(contentEl.getAttribute('data-state')).toBe('open');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.provider.props).toMatchObject({ 'data-state': 'open' });
+		expect(result.trigger.props).toMatchObject({ 'aria-expanded': 'true' });
+		expect(result.content.props).toMatchObject({ 'data-state': 'open' });
 
 		result.provider.toggle();
 		await flushRuntimeTrigger();
 		expect(opts.open.current).toBe(false);
 		expect(result.content.props.hidden).toBe(true);
-		expect(root.getAttribute('data-state')).toBe('closed');
-		expect(triggerEl.getAttribute('aria-expanded')).toBe('false');
-		expect(contentEl.getAttribute('data-state')).toBe('closed');
+		expect(result.provider.props).toMatchObject({ 'data-state': 'closed' });
+		expect(result.trigger.props).toMatchObject({ 'aria-expanded': 'false' });
+		expect(result.content.props).toMatchObject({ 'data-state': 'closed' });
 
 		cleanup();
 		dom.dispose();
@@ -179,10 +185,11 @@ describe('CollapsibleProvider', () => {
 		});
 
 		await tick();
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
 		expect(result.trigger.props.disabled).toBe(true);
-		expect(root.getAttribute('data-disabled')).toBe('');
-		expect(triggerEl.getAttribute('data-disabled')).toBe('');
-		expect(contentEl.getAttribute('data-disabled')).toBe('');
+		expect(result.provider.props).toMatchObject({ 'data-disabled': '' });
+		expect(result.trigger.props).toMatchObject({ 'data-disabled': '' });
+		expect(result.content.props).toMatchObject({ 'data-disabled': '' });
 
 		result.provider.toggle();
 		await flushRuntimeTrigger();
diff --git a/src/uix/soma/components/collapsible/collapsible-provider.svelte.ts b/src/uix/soma/components/collapsible/collapsible-provider.svelte.ts
index d9b5a13c0..eb9a9dbac 100644
--- a/src/uix/soma/components/collapsible/collapsible-provider.svelte.ts
+++ b/src/uix/soma/components/collapsible/collapsible-provider.svelte.ts
@@ -75,8 +75,7 @@ export class CollapsibleProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: CollapsibleProvider.ctx,
-			syncAttrs: true
+			context: CollapsibleProvider.ctx
 		});
 	}
 
@@ -115,8 +114,7 @@ export class CollapsibleTriggerProvider {
 		this.runtimePart = this.provider.runtime.part('trigger', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -155,8 +153,7 @@ export class CollapsibleContentProvider {
 		this.runtimePart = this.provider.runtime.part('content', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/combobox/combobox-provider.svelte.ts b/src/uix/soma/components/combobox/combobox-provider.svelte.ts
index 78a283c05..9b24340f9 100644
--- a/src/uix/soma/components/combobox/combobox-provider.svelte.ts
+++ b/src/uix/soma/components/combobox/combobox-provider.svelte.ts
@@ -137,8 +137,7 @@ export class ComboboxProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: ComboboxProvider.ctx,
-			syncAttrs: true
+			context: ComboboxProvider.ctx
 		});
 
 		const shell = createFloatingShellRoot({
diff --git a/src/uix/soma/components/cropper/cropper-provider.svelte.ts b/src/uix/soma/components/cropper/cropper-provider.svelte.ts
index f72210f36..b6a34485e 100644
--- a/src/uix/soma/components/cropper/cropper-provider.svelte.ts
+++ b/src/uix/soma/components/cropper/cropper-provider.svelte.ts
@@ -107,7 +107,8 @@ function loadImage(win: Window, src: string): Promise<HTMLImageElement | null> {
 // ── Root provider ────────────────────────────────────────────────────────────
 
 interface CropperOpts
-	extends WithRefOpts,
+	extends
+		WithRefOpts,
 		StateProps<{ crop: CropRect }>,
 		ActiveProps<{
 			src: string | null | undefined;
@@ -169,8 +170,7 @@ export class CropperProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: CropperProvider.ctx,
-			syncAttrs: true
+			context: CropperProvider.ctx
 		});
 
 		// Fixed-size crop: pin the selection to `fixedSize` (respecting `aspect`),
@@ -191,10 +191,7 @@ export class CropperProvider {
 				x: clamp(cx - width / 2, 0, 1 - width),
 				y: clamp(cy - height / 2, 0, 1 - height)
 			};
-			if (
-				Math.abs(next.width - c.width) > 1e-6 ||
-				Math.abs(next.height - c.height) > 1e-6
-			) {
+			if (Math.abs(next.width - c.width) > 1e-6 || Math.abs(next.height - c.height) > 1e-6) {
 				this.opts.crop.current = next;
 			}
 		});
@@ -365,8 +362,7 @@ export class CropperViewportProvider {
 		this.runtimePart = this.provider.runtime.part('viewport', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 		// Register the viewport element with the root for px-size lookups.
 		this.provider.viewportEl = opts.ref.current;
@@ -465,8 +461,7 @@ export class CropperSelectionProvider {
 			props: {
 				shape: () => this.provider.opts.shape.current,
 				dragging: () => this.provider.dragging
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
@@ -535,8 +530,7 @@ export class CropperGridProvider {
 		this.runtimePart = this.provider.runtime.part('grid', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -570,8 +564,7 @@ export class CropperHandleProvider {
 			owner: this,
 			props: {
 				corner: () => this.opts.corner.current
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
diff --git a/src/uix/soma/components/css-field/css-field-provider.svelte.ts b/src/uix/soma/components/css-field/css-field-provider.svelte.ts
index 9da94df1c..a26df53d1 100644
--- a/src/uix/soma/components/css-field/css-field-provider.svelte.ts
+++ b/src/uix/soma/components/css-field/css-field-provider.svelte.ts
@@ -136,7 +136,6 @@ interface CssFieldOpts
 		}> {}
 
 export class CssFieldProvider {
-
 	readonly opts: CssFieldOpts;
 	readonly runtimePart: SomaRuntimePart<typeof cssFieldMorfo, 'provider'>;
 	readonly soma: Soma;
@@ -196,8 +195,7 @@ export class CssFieldProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: CssFieldProvider.ctx,
-			syncAttrs: true
+			context: CssFieldProvider.ctx
 		});
 
 		this.resolvedDir = readableActive(() => resolveDir(opts.dir, this.soma));
@@ -496,7 +494,7 @@ export class CssFieldProvider {
 
 	readonly props = $derived.by(() =>
 		this.runtimePart.assert({
-			...this.runtimePart.props,
+			...this.runtimePart.props
 			// The attribute carries the RAW assertion, never the resolved value:
 			// omitted when nobody asserted a direction, so the element inherits
 			// instead of forcing `ltr`. `this.dir` stays for the maths.
diff --git a/src/uix/soma/components/date-field/date-field-provider.svelte.ts b/src/uix/soma/components/date-field/date-field-provider.svelte.ts
index c29ddbe62..c0f0dde5b 100644
--- a/src/uix/soma/components/date-field/date-field-provider.svelte.ts
+++ b/src/uix/soma/components/date-field/date-field-provider.svelte.ts
@@ -285,8 +285,7 @@ export class DateFieldProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: DateFieldProvider.ctx,
-			syncAttrs: true
+			context: DateFieldProvider.ctx
 		});
 
 		this.segmentValues = initializeSegmentValues(this.inferredGranularity);
@@ -1002,8 +1001,7 @@ export class DateFieldLabelProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			onRefChange: (v) => this.provider.setLabelNode(v),
-			syncAttrs: true
+			onRefChange: (v) => this.provider.setLabelNode(v)
 		});
 		this.provider.setLabelNode(opts.ref.current);
 	}
diff --git a/src/uix/soma/components/date-range-field/date-range-field-provider.svelte.ts b/src/uix/soma/components/date-range-field/date-range-field-provider.svelte.ts
index 66990ed20..6e0c419cb 100644
--- a/src/uix/soma/components/date-range-field/date-range-field-provider.svelte.ts
+++ b/src/uix/soma/components/date-range-field/date-range-field-provider.svelte.ts
@@ -122,8 +122,7 @@ export class DateRangeFieldProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: DateRangeFieldProvider.ctx,
-			syncAttrs: true
+			context: DateRangeFieldProvider.ctx
 		});
 	}
 
@@ -205,8 +204,7 @@ export class DateRangeFieldLabelProvider {
 			owner: this,
 			onRefChange: (v) => {
 				this.provider.labelNode = v;
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
diff --git a/src/uix/soma/components/dialog/dialog-provider.svelte.test.ts b/src/uix/soma/components/dialog/dialog-provider.svelte.test.ts
index 199b406e8..891a4948c 100644
--- a/src/uix/soma/components/dialog/dialog-provider.svelte.test.ts
+++ b/src/uix/soma/components/dialog/dialog-provider.svelte.test.ts
@@ -92,8 +92,7 @@ describe('DialogProvider', () => {
 			p.contentId.current = 'dialog-content';
 			p.runtime.part('content', {
 				id: state('dialog-content'),
-				ref: state<HTMLElement | null>(targetOverride),
-				syncAttrs: true
+				ref: state<HTMLElement | null>(targetOverride)
 			});
 			return p;
 		});
@@ -108,8 +107,13 @@ describe('DialogProvider', () => {
 		await provider.dismissWith('dismiss');
 
 		expect(opts.open.current).toBe(false);
+		// `data-last-action` is a PREWRITE (a commit the morfo declares) — the
+		// one imperative writer that survives fase C2c.
 		expect(targetOverride.getAttribute('data-last-action')).toBe('dismissed');
-		expect(targetOverride.getAttribute('data-state')).toBe('closed');
+		// `data-state` reaches the DOM through the render bag a Svelte spread
+		// carries in production; this test renders nothing, so the state assert
+		// lives on the source of truth (`opts.open` above) — the bag→DOM leg is
+		// pinned by the runtime suite and morfo:check.
 		expect(eventEngine.emit).toHaveBeenCalledWith(
 			expect.objectContaining({
 				name: 'emerge-close',
diff --git a/src/uix/soma/components/dialog/dialog-provider.svelte.ts b/src/uix/soma/components/dialog/dialog-provider.svelte.ts
index 307e4e8f3..20775605c 100644
--- a/src/uix/soma/components/dialog/dialog-provider.svelte.ts
+++ b/src/uix/soma/components/dialog/dialog-provider.svelte.ts
@@ -195,8 +195,7 @@ export class DialogProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: DialogProvider.ctx,
-			syncAttrs: true
+			context: DialogProvider.ctx
 		});
 	}
 
@@ -251,10 +250,7 @@ export class DialogProvider {
 		return this.triggerClose(cause, opts);
 	}
 
-	private async triggerClose(
-		cause: DismissCause,
-		opts: { message?: string } = {}
-	): Promise<void> {
+	private async triggerClose(cause: DismissCause, opts: { message?: string } = {}): Promise<void> {
 		// Imperative prewrite of `data-last-action` since the morfo's
 		// polymorphic `emerge-close` can't bind a single `prewrite` per call. It is
 		// CONTENT's exit-cause tint (the eidos recipe reads it there), so it
@@ -310,8 +306,7 @@ export class DialogTriggerProvider {
 			owner: this,
 			onRefChange: (el) => {
 				this.provider.triggerNode.current = el;
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
@@ -335,19 +330,22 @@ export class DialogTriggerProvider {
 
 // ── Content ─────────────────────────────────────────────────────────────────
 
-interface DialogContentOpts extends WithRefOpts, ActiveProps<{
-	trapFocus: boolean | undefined;
-	loop: boolean;
-	preventScroll: boolean | undefined;
-	restoreScrollDelay: number;
-	onOpenAutoFocus: (e: Event) => void;
-	onCloseAutoFocus: (e: Event) => void;
-	onEscapeKeydown: (e: KeyboardEvent) => void;
-	escapeKeydownBehavior: DismissalBehavior | undefined;
-	onInteractOutside: (e: PointerEvent) => void;
-	interactOutsideBehavior: DismissalBehavior | undefined;
-	onFocusOutside: (e: FocusEvent) => void;
-}> {}
+interface DialogContentOpts
+	extends
+		WithRefOpts,
+		ActiveProps<{
+			trapFocus: boolean | undefined;
+			loop: boolean;
+			preventScroll: boolean | undefined;
+			restoreScrollDelay: number;
+			onOpenAutoFocus: (e: Event) => void;
+			onCloseAutoFocus: (e: Event) => void;
+			onEscapeKeydown: (e: KeyboardEvent) => void;
+			escapeKeydownBehavior: DismissalBehavior | undefined;
+			onInteractOutside: (e: PointerEvent) => void;
+			interactOutsideBehavior: DismissalBehavior | undefined;
+			onFocusOutside: (e: FocusEvent) => void;
+		}> {}
 
 export class DialogContentProvider {
 	static create(opts: DialogContentOpts) {
@@ -381,8 +379,7 @@ export class DialogContentProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			onRefChange: (el) => this.provider.setContentRef(el),
-			syncAttrs: true
+			onRefChange: (el) => this.provider.setContentRef(el)
 		});
 
 		this.focusScope = FocusScope.use({
@@ -449,7 +446,8 @@ export class DialogContentProvider {
 	readonly props = $derived.by(() => ({
 		...this.runtimePart.props,
 		// `role` is provider-owned (variant-dependent) — the morfo no longer
-		// declares it, so syncAttrs can't overwrite this back to 'dialog' (dialog-001).
+		// declares it, so the render bag carries no 'dialog' literal to race
+		// this override (dialog-001).
 		role: this.provider.opts.variant.current,
 		'data-nested': this.provider.isNested ? '' : undefined,
 		'data-nested-open': this.provider.hasNestedOpen ? '' : undefined,
@@ -484,8 +482,7 @@ export class DialogOverlayProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			onRefChange: (el) => this.provider.setOverlayRef(el),
-			syncAttrs: true
+			onRefChange: (el) => this.provider.setOverlayRef(el)
 		});
 	}
 
@@ -527,8 +524,7 @@ export class DialogTitleProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			props: { level: () => this.opts.level.current },
-			syncAttrs: true
+			props: { level: () => this.opts.level.current }
 		});
 	}
 
@@ -557,8 +553,7 @@ export class DialogDescriptionProvider {
 		this.runtimePart = this.provider.runtime.part('description', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -586,8 +581,7 @@ export class DialogCloseProvider {
 		this.runtimePart = this.provider.runtime.part('close', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/drawer/drawer-provider.svelte.test.ts b/src/uix/soma/components/drawer/drawer-provider.svelte.test.ts
index a581ed30b..0f8e54a55 100644
--- a/src/uix/soma/components/drawer/drawer-provider.svelte.test.ts
+++ b/src/uix/soma/components/drawer/drawer-provider.svelte.test.ts
@@ -135,8 +135,7 @@ describe('DrawerProvider', () => {
 			p.contentId.current = 'drawer-content';
 			p.runtime.part('content', {
 				id: state('drawer-content'),
-				ref: state<HTMLElement | null>(targetOverride),
-				syncAttrs: true
+				ref: state<HTMLElement | null>(targetOverride)
 			});
 			return p;
 		});
@@ -151,8 +150,11 @@ describe('DrawerProvider', () => {
 		// lands where the user left it. Resetting it here would also have been a
 		// silent write — the binding saw it, the callback did not.
 		expect(opts.activeSnapPoint.current).toBe(0.5);
+		// `data-last-action` is a PREWRITE — the one imperative writer that
+		// survives fase C2c. `data-state` travels in the render bag (asserted
+		// via `opts.open` above; the bag→DOM leg is the runtime suite's and
+		// morfo:check's to pin).
 		expect(targetOverride.getAttribute('data-last-action')).toBe('dismissed');
-		expect(targetOverride.getAttribute('data-state')).toBe('closed');
 		expect(eventEngine.emit).toHaveBeenCalledWith(
 			expect.objectContaining({
 				name: 'emerge-close',
diff --git a/src/uix/soma/components/drawer/drawer-provider.svelte.ts b/src/uix/soma/components/drawer/drawer-provider.svelte.ts
index 39f9caa6b..90c21b739 100644
--- a/src/uix/soma/components/drawer/drawer-provider.svelte.ts
+++ b/src/uix/soma/components/drawer/drawer-provider.svelte.ts
@@ -274,8 +274,7 @@ export class DrawerProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: DrawerProvider.ctx,
-			syncAttrs: true
+			context: DrawerProvider.ctx
 		});
 	}
 
@@ -410,8 +409,7 @@ export class DrawerTriggerProvider {
 			onRefChange: (el) => {
 				this.provider.triggerNode.current = el;
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -504,8 +502,7 @@ export class DrawerContentProvider {
 			id: opts.id,
 			ref: opts.ref,
 			onRefChange: (el) => this.provider.setContentRef(el),
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 
 		// ── Focus scope ──────────────────────────────────────────────────────
@@ -607,13 +604,13 @@ export class DrawerContentProvider {
 			lastAxisOffset = axisOffsetToward;
 
 			return {
-			// The gesture sounds by REPETITION: this fires at the drag's own
-			// rhythm, so `step` per emission makes the speed of the gesture the
-			// speed of the clicking — a ratchet. It replaced a resolver that
-			// synthesised pitch from position and velocity, the last arithmetic
-			// in the sound path. Trade-off signed on 2026-08-06: the rhythm
-			// carries the speed, but position no longer maps to pitch.
-			sound: 'step' as const,
+				// The gesture sounds by REPETITION: this fires at the drag's own
+				// rhythm, so `step` per emission makes the speed of the gesture the
+				// speed of the clicking — a ratchet. It replaced a resolver that
+				// synthesised pitch from position and velocity, the last arithmetic
+				// in the sound path. Trade-off signed on 2026-08-06: the rhythm
+				// carries the speed, but position no longer maps to pitch.
+				sound: 'step' as const
 			};
 		};
 		const flushDragProgress = () => {
@@ -1102,8 +1099,7 @@ export class DrawerOverlayProvider {
 			id: opts.id,
 			ref: opts.ref,
 			onRefChange: (el) => this.provider.setOverlayRef(el),
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -1157,8 +1153,7 @@ export class DrawerHandleProvider {
 			onRefChange: (el) => {
 				this.provider.handleNode.current = el;
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -1190,8 +1185,7 @@ export class DrawerTitleProvider {
 			id: opts.id,
 			ref: opts.ref,
 			props: { level: () => this.opts.level.current },
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -1222,8 +1216,7 @@ export class DrawerDescriptionProvider {
 		this.runtimePart = this.provider.runtime.part('description', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -1251,8 +1244,7 @@ export class DrawerCloseProvider {
 		this.runtimePart = this.provider.runtime.part('close', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/editable/editable-provider.svelte.test.ts b/src/uix/soma/components/editable/editable-provider.svelte.test.ts
index ba232440c..389794cc5 100644
--- a/src/uix/soma/components/editable/editable-provider.svelte.test.ts
+++ b/src/uix/soma/components/editable/editable-provider.svelte.test.ts
@@ -152,10 +152,11 @@ describe('EditableProvider', () => {
 		});
 
 		await tick();
-		expect(root.getAttribute('data-editing')).toBe('');
-		expect(root.hasAttribute('data-empty')).toBe(false);
-		expect(areaEl.getAttribute('data-editing')).toBe('');
-		expect(areaEl.hasAttribute('data-disabled')).toBe(false);
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.provider.props).toMatchObject({ 'data-editing': '' });
+		expect('data-empty' in result.provider.props).toBe(false);
+		expect(result.area.props).toMatchObject({ 'data-editing': '' });
+		expect('data-disabled' in result.area.props).toBe(false);
 
 		cleanup();
 		dom.dispose();
diff --git a/src/uix/soma/components/editable/editable-provider.svelte.ts b/src/uix/soma/components/editable/editable-provider.svelte.ts
index 83da5b0d3..9831a8e69 100644
--- a/src/uix/soma/components/editable/editable-provider.svelte.ts
+++ b/src/uix/soma/components/editable/editable-provider.svelte.ts
@@ -76,8 +76,7 @@ export class EditableProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: EditableProvider.ctx,
-			syncAttrs: true
+			context: EditableProvider.ctx
 		});
 
 		this.draft = opts.value.current;
@@ -153,9 +152,9 @@ export class EditableProvider {
 
 	readonly props = $derived.by(() =>
 		this.runtimePart.assert({
-			// syncAttrs writes the morfo attrs (data-editing/empty/disabled/readonly/
-			// required/invalid + aria-required/invalid) imperatively via dom.apply —
-			// the provider no longer re-declares them here.
+			// The render bag resolves the morfo attrs (data-editing/empty/disabled/
+			// readonly/required/invalid + aria-required/invalid) — the provider
+			// no longer re-declares them here.
 			...this.runtimePart.props
 		} as const)
 	);
@@ -180,8 +179,7 @@ export class EditableAreaProvider {
 		this.runtimePart = this.provider.runtime.part('area', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -211,8 +209,7 @@ export class EditableControlProvider {
 		this.runtimePart = this.provider.runtime.part('control', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/emoji-picker/emoji-picker-provider.svelte.ts b/src/uix/soma/components/emoji-picker/emoji-picker-provider.svelte.ts
index e75f33f0a..875d59dde 100644
--- a/src/uix/soma/components/emoji-picker/emoji-picker-provider.svelte.ts
+++ b/src/uix/soma/components/emoji-picker/emoji-picker-provider.svelte.ts
@@ -86,8 +86,7 @@ export class EmojiPickerProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: EmojiPickerProvider.ctx,
-			syncAttrs: true
+			context: EmojiPickerProvider.ctx
 		});
 	}
 
@@ -118,7 +117,8 @@ export class EmojiPickerProvider {
 	/** Categories to show as tabs — `recents` first (if enabled + non-empty). */
 	readonly categories = $derived.by<EmojiCategory[]>(() => {
 		const groups = EMOJI_GROUPS.map((g) => g.index);
-		if (this.opts.showRecents.current && this.recentEntries.length > 0) return ['recents', ...groups];
+		if (this.opts.showRecents.current && this.recentEntries.length > 0)
+			return ['recents', ...groups];
 		return groups;
 	});
 
@@ -249,8 +249,7 @@ export class EmojiPickerContentProvider {
 		this.runtimePart = this.provider.runtime.part('content', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -283,8 +282,7 @@ export class EmojiPickerGridProvider {
 		this.runtimePart = this.provider.runtime.part('grid', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 		this.commandList = CommandListProvider.create({ id: opts.id, ref: opts.ref });
 	}
@@ -326,8 +324,7 @@ export class EmojiPickerOptionProvider {
 		this.runtimePart = this.runtime.part('option', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 		this.commandItem = CommandItemProvider.create({
 			id: opts.id,
@@ -368,8 +365,7 @@ export class EmojiPickerPreviewProvider {
 		this.runtimePart = this.provider.runtime.part('preview', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/feed/feed-provider.svelte.test.ts b/src/uix/soma/components/feed/feed-provider.svelte.test.ts
index 7db12c87c..e8ac56aae 100644
--- a/src/uix/soma/components/feed/feed-provider.svelte.test.ts
+++ b/src/uix/soma/components/feed/feed-provider.svelte.test.ts
@@ -130,20 +130,21 @@ describe('FeedProvider', () => {
 		expect(result.first.descriptionId.current).toBe('feed-description-1');
 
 		await tick();
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
 		expect(result.first.snippetProps).toEqual({ index: 0, total: 10 });
 		expect(result.second.snippetProps).toEqual({ index: 1, total: 10 });
-		expect(root.getAttribute('role')).toBe('feed');
+		expect(result.provider.props).toMatchObject({ role: 'feed', 'aria-busy': 'true' });
 		// Naming default: ships in the render bag (consumerWins, A-85).
 		expect(result.provider.props).toMatchObject({ 'aria-label': 'Feed' });
-		expect(root.getAttribute('aria-busy')).toBe('true');
-		expect(firstEl.getAttribute('role')).toBe('article');
-		expect(firstEl.getAttribute('aria-posinset')).toBe('1');
-		expect(firstEl.getAttribute('aria-setsize')).toBe('10');
-		expect(firstEl.getAttribute('aria-labelledby')).toBe('feed-title-1');
-		expect(firstEl.getAttribute('aria-describedby')).toBe('feed-description-1');
-		expect(titleEl.getAttribute('role')).toBe('heading');
-		expect(titleEl.getAttribute('aria-level')).toBe('3');
-		expect(secondEl.getAttribute('aria-posinset')).toBe('2');
+		expect(result.first.props).toMatchObject({
+			role: 'article',
+			'aria-posinset': 1,
+			'aria-setsize': 10,
+			'aria-labelledby': 'feed-title-1',
+			'aria-describedby': 'feed-description-1'
+		});
+		expect(result.title.props).toMatchObject({ role: 'heading', 'aria-level': 3 });
+		expect(result.second.props).toMatchObject({ 'aria-posinset': 2 });
 
 		const next = keyEvent('PageDown', firstEl);
 		result.first.onkeydown(next as never);
@@ -166,7 +167,7 @@ describe('FeedProvider', () => {
 		opts.ariaLabelledby.current = 'feed-title-1';
 		await tick();
 		expect(result.provider.props).not.toHaveProperty('aria-label');
-		expect(root.getAttribute('aria-labelledby')).toBe('feed-title-1');
+		expect(result.provider.props).toMatchObject({ 'aria-labelledby': 'feed-title-1' });
 
 		cleanup();
 		dom.dispose();
@@ -222,11 +223,13 @@ describe('FeedProvider', () => {
 		expect(result.title.resolvedLevel).toBe(3);
 
 		await tick();
-		expect(threadEl.getAttribute('role')).toBe('feed');
-		expect(threadEl.getAttribute('data-level')).toBe('2');
-		expect(threadEl.getAttribute('aria-labelledby')).toBe('feed-parent-title');
-		expect(nestedEl.getAttribute('data-level')).toBe('2');
-		expect(nestedEl.getAttribute('aria-setsize')).toBe('-1');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.thread.props).toMatchObject({
+			role: 'feed',
+			'data-level': 2,
+			'aria-labelledby': 'feed-parent-title'
+		});
+		expect(result.nested.props).toMatchObject({ 'data-level': 2, 'aria-setsize': -1 });
 
 		cleanup();
 		dom.dispose();
@@ -293,8 +296,8 @@ describe('FeedProvider', () => {
 		expect(onLoadMore).toHaveBeenCalledOnce();
 
 		await tick();
-		expect(sentinelEl.getAttribute('aria-hidden')).toBe('true');
-		expect(sentinelEl.getAttribute('data-intersecting')).toBe('');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.sentinel.props).toMatchObject({ 'aria-hidden': 'true', 'data-intersecting': '' });
 
 		cleanup();
 		expect(observerCleanup).toHaveBeenCalledOnce();
diff --git a/src/uix/soma/components/feed/feed-provider.svelte.ts b/src/uix/soma/components/feed/feed-provider.svelte.ts
index fcde7e3e1..8902e6ce1 100644
--- a/src/uix/soma/components/feed/feed-provider.svelte.ts
+++ b/src/uix/soma/components/feed/feed-provider.svelte.ts
@@ -54,8 +54,7 @@ export class FeedProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: FeedProvider.ctx,
-			syncAttrs: true
+			context: FeedProvider.ctx
 		});
 	}
 
@@ -190,8 +189,7 @@ export class FeedThreadProvider {
 			},
 			parts: {
 				'article-title': () => this.parentArticle.titleId.current || undefined
-			},
-			syncAttrs: true
+			}
 		});
 		this.level = this.parentArticle.level + 1;
 	}
@@ -248,8 +246,7 @@ export class FeedArticleProvider {
 			parts: {
 				'article-title': () => this.titleId.current || undefined,
 				'article-description': () => this.descriptionId.current || undefined
-			},
-			syncAttrs: true
+			}
 		});
 		this.level = this.thread ? this.thread.level : 1;
 	}
@@ -328,8 +325,7 @@ export class FeedArticleTitleProvider {
 			owner: this,
 			props: {
 				level: () => this.resolvedLevel
-			},
-			syncAttrs: true
+			}
 		});
 		// A30: direct assignment.
 		this.article.titleId.current = opts.id.current;
@@ -429,8 +425,7 @@ export class FeedSentinelProvider {
 			owner: this,
 			props: {
 				intersecting: () => this.intersecting
-			},
-			syncAttrs: true
+			}
 		});
 
 		$effect(() => {
diff --git a/src/uix/soma/components/field-langs/field-langs-provider.svelte.ts b/src/uix/soma/components/field-langs/field-langs-provider.svelte.ts
index 86d6f2a23..8aa586dfc 100644
--- a/src/uix/soma/components/field-langs/field-langs-provider.svelte.ts
+++ b/src/uix/soma/components/field-langs/field-langs-provider.svelte.ts
@@ -73,16 +73,14 @@ export class FieldLangsProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: FieldLangsProvider.ctx,
-			syncAttrs: true
+			context: FieldLangsProvider.ctx
 		});
 	}
 
 	// ── Language set ───────────────────────────────────────────────────────────
 	readonly langSpecs = $derived.by(() =>
-		this.opts.languages.current.map(
-			(l): { code: LangCode; label?: string; dir?: Direction } =>
-				typeof l === 'string' ? { code: l } : l
+		this.opts.languages.current.map((l): { code: LangCode; label?: string; dir?: Direction } =>
+			typeof l === 'string' ? { code: l } : l
 		)
 	);
 	readonly langCodes = $derived.by(() => this.langSpecs.map((s) => s.code));
diff --git a/src/uix/soma/components/field/field-provider.svelte.test.ts b/src/uix/soma/components/field/field-provider.svelte.test.ts
index e63bc4496..3724b1cb7 100644
--- a/src/uix/soma/components/field/field-provider.svelte.test.ts
+++ b/src/uix/soma/components/field/field-provider.svelte.test.ts
@@ -167,19 +167,22 @@ describe('FieldProvider', () => {
 		expect(result.suffix.props).toMatchObject({ 'aria-hidden': 'true' });
 
 		await tick();
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
 		// data-state pruned (S10): the resolved state no longer materializes as
 		// an attr — invalid/disabled/readonly flags are the CSS surface.
-		expect(root.hasAttribute('data-state')).toBe(false);
-		expect(root.getAttribute('data-required')).toBe('');
-		expect(requiredEl.getAttribute('data-required')).toBe('');
-		// aria-hidden is applied to the DOM via syncAttrs (not the props object).
-		expect(requiredEl.getAttribute('aria-hidden')).toBe('true');
-		expect(root.getAttribute('data-invalid')).toBe('');
-		expect(root.getAttribute('data-field-name')).toBe('email');
-		expect(labelEl.getAttribute('for')).toBe('field-input');
-		expect(controlEl.hasAttribute('data-state')).toBe(false);
-		expect(errorEl.getAttribute('role')).toBe('alert');
-		expect(errorEl.getAttribute('aria-live')).toBe('polite');
+		expect('data-state' in result.provider.props).toBe(false);
+		expect(result.provider.props).toMatchObject({
+			'data-required': '',
+			'data-invalid': '',
+			'data-field-name': 'email'
+		});
+		expect(result.required.props).toMatchObject({
+			'data-required': '',
+			'aria-hidden': 'true'
+		});
+		expect(result.label.props).toMatchObject({ for: 'field-input' });
+		expect('data-state' in result.control.props).toBe(false);
+		expect(result.error.props).toMatchObject({ role: 'alert', 'aria-live': 'polite' });
 
 		cleanup();
 		dom.dispose();
diff --git a/src/uix/soma/components/field/field-provider.svelte.ts b/src/uix/soma/components/field/field-provider.svelte.ts
index 409ae42f7..c07ff0bb8 100644
--- a/src/uix/soma/components/field/field-provider.svelte.ts
+++ b/src/uix/soma/components/field/field-provider.svelte.ts
@@ -78,8 +78,7 @@ export class FieldProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: FieldProvider.ctx,
-			syncAttrs: true
+			context: FieldProvider.ctx
 		});
 
 		// Auto-register / unregister with the parent Form (if `name` is set).
@@ -195,8 +194,7 @@ export class FieldLabelProvider {
 		this.runtimePart = this.provider.runtime.part('label', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 		this.provider.labelId.current = opts.id.current;
 	}
@@ -227,13 +225,11 @@ export class FieldRequiredIndicatorProvider {
 		this.runtimePart = this.provider.runtime.part('required-indicator', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
-	// syncAttrs applies the morfo's aria-hidden via dom.apply — getter is
-	// identity-only.
+	// The render bag resolves the morfo's aria-hidden — nothing to add here.
 	readonly props = $derived.by(() =>
 		this.runtimePart.assert({
 			...this.runtimePart.props
@@ -260,13 +256,11 @@ export class FieldOptionalIndicatorProvider {
 		this.runtimePart = this.provider.runtime.part('optional-indicator', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
-	// syncAttrs applies the morfo's aria-hidden via dom.apply — getter is
-	// identity-only.
+	// The render bag resolves the morfo's aria-hidden — nothing to add here.
 	readonly props = $derived.by(() =>
 		this.runtimePart.assert({
 			...this.runtimePart.props
@@ -293,8 +287,7 @@ export class FieldControlProvider {
 		this.runtimePart = this.provider.runtime.part('control', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -417,8 +410,7 @@ export class FieldHelperTextProvider {
 		this.runtimePart = this.provider.runtime.part('helper-text', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 		this.provider.helperId.current = opts.id.current;
 
@@ -456,8 +448,7 @@ export class FieldErrorTextProvider {
 		this.runtimePart = this.provider.runtime.part('error-text', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 		this.provider.errorId.current = opts.id.current;
 
diff --git a/src/uix/soma/components/float-panel/float-panel-provider.svelte.ts b/src/uix/soma/components/float-panel/float-panel-provider.svelte.ts
index d2c0eb7a7..6c1614871 100644
--- a/src/uix/soma/components/float-panel/float-panel-provider.svelte.ts
+++ b/src/uix/soma/components/float-panel/float-panel-provider.svelte.ts
@@ -214,8 +214,7 @@ export class FloatPanelProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: FloatPanelProvider.ctx,
-			syncAttrs: true
+			context: FloatPanelProvider.ctx
 		});
 
 		// Register in the shared stacking order while open; remove on close/unmount.
@@ -355,7 +354,8 @@ export class FloatPanelProvider {
 		priority: 'polite' | 'assertive' = 'polite'
 	): void {
 		let msg = this.soma.langs.ts(lang);
-		if (params) for (const [k, val] of Object.entries(params)) msg = msg.replaceAll(`{${k}}`, String(val));
+		if (params)
+			for (const [k, val] of Object.entries(params)) msg = msg.replaceAll(`{${k}}`, String(val));
 		this.soma.uix?.announce?.(msg, priority);
 	}
 	private posParams(p: FloatPanelPosition) {
@@ -426,15 +426,40 @@ export class FloatPanelProvider {
 		const before = this.currentPos;
 		let { x, y } = before;
 		switch (e.key) {
-			case 'ArrowUp': y -= step; this.kbAxis = 'y'; break;
-			case 'ArrowDown': y += step; this.kbAxis = 'y'; break;
-			case 'ArrowLeft': x -= step; this.kbAxis = 'x'; break;
-			case 'ArrowRight': x += step; this.kbAxis = 'x'; break;
-			case 'PageUp': y -= KB_STEP_PAGE; this.kbAxis = 'y'; break;
-			case 'PageDown': y += KB_STEP_PAGE; this.kbAxis = 'y'; break;
-			case 'Home': if (this.kbAxis === 'x') x = bounds.left; else y = bounds.top; break;
-			case 'End': if (this.kbAxis === 'x') x = bounds.right - size.width; else y = bounds.bottom - size.height; break;
-			default: return;
+			case 'ArrowUp':
+				y -= step;
+				this.kbAxis = 'y';
+				break;
+			case 'ArrowDown':
+				y += step;
+				this.kbAxis = 'y';
+				break;
+			case 'ArrowLeft':
+				x -= step;
+				this.kbAxis = 'x';
+				break;
+			case 'ArrowRight':
+				x += step;
+				this.kbAxis = 'x';
+				break;
+			case 'PageUp':
+				y -= KB_STEP_PAGE;
+				this.kbAxis = 'y';
+				break;
+			case 'PageDown':
+				y += KB_STEP_PAGE;
+				this.kbAxis = 'y';
+				break;
+			case 'Home':
+				if (this.kbAxis === 'x') x = bounds.left;
+				else y = bounds.top;
+				break;
+			case 'End':
+				if (this.kbAxis === 'x') x = bounds.right - size.width;
+				else y = bounds.bottom - size.height;
+				break;
+			default:
+				return;
 		}
 		const next = this.clampPosition(this.snapPx(x), this.snapPx(y), size, bounds);
 		if (next.x === before.x && next.y === before.y) {
@@ -481,18 +506,30 @@ export class FloatPanelProvider {
 		const before = this.currentSize;
 		let { width, height } = before;
 		switch (e.key) {
-			case 'ArrowRight': width += step; break;
-			case 'ArrowLeft': width -= step; break;
-			case 'ArrowDown': height += step; break;
-			case 'ArrowUp': height -= step; break;
-			case 'Home': width = this.opts.minWidth.current; height = this.opts.minHeight.current; break;
+			case 'ArrowRight':
+				width += step;
+				break;
+			case 'ArrowLeft':
+				width -= step;
+				break;
+			case 'ArrowDown':
+				height += step;
+				break;
+			case 'ArrowUp':
+				height -= step;
+				break;
+			case 'Home':
+				width = this.opts.minWidth.current;
+				height = this.opts.minHeight.current;
+				break;
 			case 'End': {
 				const b = this.maximizedRect();
 				width = this.opts.maxWidth.current ?? b.width;
 				height = this.opts.maxHeight.current ?? b.height;
 				break;
 			}
-			default: return;
+			default:
+				return;
 		}
 		const growing = width > before.width || height > before.height;
 		const next = this.clampSize(this.snapPx(width), this.snapPx(height));
@@ -642,11 +679,7 @@ export class FloatPanelProvider {
 		// Centered — within the container (absolute) or the viewport (fixed).
 		if (strategy === 'absolute') {
 			const bd = this.boundsRect();
-			return this.clampPosition(
-				(bd.right - size.width) / 2,
-				(bd.bottom - size.height) / 2,
-				size
-			);
+			return this.clampPosition((bd.right - size.width) / 2, (bd.bottom - size.height) / 2, size);
 		}
 		const win = this.soma.dom.getWindow();
 		return this.clampPosition(
@@ -724,7 +757,9 @@ export class FloatPanelProvider {
 		if (this.contentRef.current)
 			this.soma.dom.writeProperty(this.contentRef.current, 'will-change', 'translate');
 		const doc = this.soma.dom.getDocument(this.dragEl);
-		const move = this.soma.dom.listen(doc, 'pointermove', (ev) => this.onDragMove(ev as PointerEvent));
+		const move = this.soma.dom.listen(doc, 'pointermove', (ev) =>
+			this.onDragMove(ev as PointerEvent)
+		);
 		const up = this.soma.dom.listen(doc, 'pointerup', (ev) => this.endDrag(ev as PointerEvent));
 		const cancel = this.soma.dom.listen(doc, 'pointercancel', (ev) =>
 			this.endDrag(ev as PointerEvent)
@@ -977,8 +1012,7 @@ export class FloatPanelTriggerProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			onRefChange: (el) => this.provider.setTriggerRef(el),
-			syncAttrs: true
+			onRefChange: (el) => this.provider.setTriggerRef(el)
 		});
 	}
 
@@ -1026,8 +1060,7 @@ export class FloatPanelContentProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			onRefChange: (el) => this.provider.setContentRef(el),
-			syncAttrs: true
+			onRefChange: (el) => this.provider.setContentRef(el)
 		});
 
 		// Focus: trap only when modal (free panels keep background interactive).
@@ -1196,8 +1229,7 @@ export class FloatPanelHeaderProvider {
 		this.runtimePart = this.provider.runtime.part('header', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -1246,8 +1278,7 @@ export class FloatPanelTitleProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			props: { level: () => this.opts.level.current },
-			syncAttrs: true
+			props: { level: () => this.opts.level.current }
 		});
 	}
 
@@ -1275,8 +1306,7 @@ export class FloatPanelCloseProvider {
 		this.runtimePart = this.provider.runtime.part('close', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -1312,8 +1342,7 @@ export class FloatPanelBodyProvider {
 		this.runtimePart = this.provider.runtime.part('body', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -1339,8 +1368,7 @@ export class FloatPanelControlsProvider {
 		this.runtimePart = this.provider.runtime.part('controls', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -1366,8 +1394,7 @@ export class FloatPanelActionProvider {
 		this.runtimePart = this.provider.runtime.part('action', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -1381,8 +1408,7 @@ export class FloatPanelActionProvider {
 
 // ── StageTrigger (minimize / maximize / restore) ─────────────────────────────
 
-interface FloatPanelStageTriggerOpts
-	extends WithRefOpts, ActiveProps<{ stage: FloatPanelStage }> {}
+interface FloatPanelStageTriggerOpts extends WithRefOpts, ActiveProps<{ stage: FloatPanelStage }> {}
 
 export class FloatPanelStageTriggerProvider {
 	static create(opts: FloatPanelStageTriggerOpts) {
@@ -1399,8 +1425,7 @@ export class FloatPanelStageTriggerProvider {
 		this.runtimePart = this.provider.runtime.part('stage-trigger', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -1435,8 +1460,7 @@ export class FloatPanelResizeHandleProvider {
 		this.runtimePart = this.provider.runtime.part('resize-handle', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -1470,8 +1494,7 @@ export class FloatPanelResizeGripProvider {
 		this.runtimePart = this.provider.runtime.part('resize-grip', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/form/form-provider.svelte.test.ts b/src/uix/soma/components/form/form-provider.svelte.test.ts
index 09a8d186f..2a7f14f41 100644
--- a/src/uix/soma/components/form/form-provider.svelte.test.ts
+++ b/src/uix/soma/components/form/form-provider.svelte.test.ts
@@ -143,8 +143,9 @@ describe('FormProvider', () => {
 		expect(provider.isSubmitted).toBe(true);
 		expect(provider.isInvalid).toBe(true);
 		expect(focusSpy).toHaveBeenCalledWith(input);
-		expect(root.getAttribute('data-invalid')).toBe('');
-		expect(root.getAttribute('data-submitted')).toBe('');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(provider.props['data-invalid']).toBe('');
+		expect(provider.props['data-submitted']).toBe('');
 
 		cleanup();
 		dom.dispose();
diff --git a/src/uix/soma/components/form/form-provider.svelte.ts b/src/uix/soma/components/form/form-provider.svelte.ts
index 54bbb32f6..35fd8392f 100644
--- a/src/uix/soma/components/form/form-provider.svelte.ts
+++ b/src/uix/soma/components/form/form-provider.svelte.ts
@@ -58,8 +58,7 @@ export class FormProvider<TForm extends Form = Form> {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: FormProvider.ctx,
-			syncAttrs: true
+			context: FormProvider.ctx
 		});
 	}
 
diff --git a/src/uix/soma/components/gradient-builder/gradient-builder-provider.svelte.ts b/src/uix/soma/components/gradient-builder/gradient-builder-provider.svelte.ts
index 92f12eaf8..38afc2fe0 100644
--- a/src/uix/soma/components/gradient-builder/gradient-builder-provider.svelte.ts
+++ b/src/uix/soma/components/gradient-builder/gradient-builder-provider.svelte.ts
@@ -99,8 +99,7 @@ export class GradientBuilderProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: GradientBuilderProvider.ctx,
-			syncAttrs: true
+			context: GradientBuilderProvider.ctx
 		});
 	}
 
@@ -310,7 +309,7 @@ export class GradientStopProvider {
 			ref: opts.ref,
 			owner: this,
 			context: GradientStopProvider.ctx,
-			syncAttrs: true,
+
 			// Per-stop sources for the morfo's value-bound aria (aria-valuenow /
 			// aria-valuetext / aria-label) — resolved via `the render bag`.
 			props: {
@@ -436,8 +435,7 @@ export class GradientTrackProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: GradientTrackProvider.ctx,
-			syncAttrs: true
+			context: GradientTrackProvider.ctx
 		});
 		// The track IS the drag surface the provider measures against.
 		$effect(() => {
diff --git a/src/uix/soma/components/gradient-picker/gradient-picker-provider.svelte.ts b/src/uix/soma/components/gradient-picker/gradient-picker-provider.svelte.ts
index ce698a60c..5f3ac843b 100644
--- a/src/uix/soma/components/gradient-picker/gradient-picker-provider.svelte.ts
+++ b/src/uix/soma/components/gradient-picker/gradient-picker-provider.svelte.ts
@@ -21,7 +21,8 @@ export const DEFAULT_PICKER_GRADIENT: Gradient = {
 // ── Root ─────────────────────────────────────────────────────────────────────
 
 interface GradientPickerOpts
-	extends ProviderOpts,
+	extends
+		ProviderOpts,
 		StateProps<{
 			/** The WORKING gradient (`picker.workingValue`) — what the editor edits. */
 			value: Gradient;
@@ -155,8 +156,7 @@ export class GradientPickerProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: GradientPickerProvider.ctx,
-			syncAttrs: true
+			context: GradientPickerProvider.ctx
 		});
 	}
 
@@ -172,8 +172,7 @@ export class GradientPickerProvider {
 // ── Trigger ───────────────────────────────────────────────────────────────────
 
 interface GradientPickerTriggerOpts
-	extends WithRefOpts,
-		ActiveProps<{ ariaLabel: string | undefined }> {}
+	extends WithRefOpts, ActiveProps<{ ariaLabel: string | undefined }> {}
 
 export class GradientPickerTriggerProvider {
 	readonly opts: GradientPickerTriggerOpts;
diff --git a/src/uix/soma/components/image-adjustments/image-adjustments-provider.svelte.ts b/src/uix/soma/components/image-adjustments/image-adjustments-provider.svelte.ts
index 37f56a3b2..0789771f0 100644
--- a/src/uix/soma/components/image-adjustments/image-adjustments-provider.svelte.ts
+++ b/src/uix/soma/components/image-adjustments/image-adjustments-provider.svelte.ts
@@ -129,7 +129,8 @@ export function computeImageFilter(
 // ── Root provider ────────────────────────────────────────────────────────────
 
 interface ImageAdjustmentsOpts
-	extends WithRefOpts,
+	extends
+		WithRefOpts,
 		StateProps<{ value: ImageAdjustmentValues }>,
 		ActiveProps<{
 			adjustments: ImageAdjustmentKey[] | undefined;
@@ -166,9 +167,7 @@ export class ImageAdjustmentsProvider {
 				'commit-reset': () => {
 					const next: ImageAdjustmentValues = {};
 					this.opts.value.current = next;
-					this.opts.onFilterChange.current?.(
-						computeImageFilter(next, this.resolvedAdjustments)
-					);
+					this.opts.onFilterChange.current?.(computeImageFilter(next, this.resolvedAdjustments));
 				}
 			}
 		});
@@ -176,8 +175,7 @@ export class ImageAdjustmentsProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: ImageAdjustmentsProvider.ctx,
-			syncAttrs: true
+			context: ImageAdjustmentsProvider.ctx
 		});
 	}
 
@@ -194,7 +192,9 @@ export class ImageAdjustmentsProvider {
 	/** True when any adjustment differs from its neutral default. */
 	readonly isModified = $derived.by(() =>
 		this.resolvedAdjustments.some(
-			(key) => (this.opts.value.current[key] ?? IMAGE_ADJUSTMENTS[key].default) !== IMAGE_ADJUSTMENTS[key].default
+			(key) =>
+				(this.opts.value.current[key] ?? IMAGE_ADJUSTMENTS[key].default) !==
+				IMAGE_ADJUSTMENTS[key].default
 		)
 	);
 
@@ -229,8 +229,7 @@ export class ImageAdjustmentsProvider {
 // ── Item ───────────────────────────────────────────────────────────────────
 
 interface ImageAdjustmentsItemOpts
-	extends WithRefOpts,
-		ActiveProps<{ adjustment: ImageAdjustmentKey }> {}
+	extends WithRefOpts, ActiveProps<{ adjustment: ImageAdjustmentKey }> {}
 
 export class ImageAdjustmentsItemProvider {
 	readonly opts: ImageAdjustmentsItemOpts;
@@ -255,8 +254,7 @@ export class ImageAdjustmentsItemProvider {
 			context: ImageAdjustmentsItemProvider.ctx,
 			props: {
 				adjustment: () => this.opts.adjustment.current
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
@@ -303,8 +301,7 @@ export class ImageAdjustmentsItemLabelProvider {
 		this.runtimePart = this.item.provider.runtime.part('item-label', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -330,8 +327,7 @@ export class ImageAdjustmentsItemValueProvider {
 		this.runtimePart = this.item.provider.runtime.part('item-value', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -357,8 +353,7 @@ export class ImageAdjustmentsResetProvider {
 		this.runtimePart = this.provider.runtime.part('reset', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/image-picker/image-picker-provider.svelte.ts b/src/uix/soma/components/image-picker/image-picker-provider.svelte.ts
index 06b26d2e5..c88069071 100644
--- a/src/uix/soma/components/image-picker/image-picker-provider.svelte.ts
+++ b/src/uix/soma/components/image-picker/image-picker-provider.svelte.ts
@@ -17,7 +17,8 @@ import type { ImagePickerFit, ImagePickerRotation, ImagePickerValue } from './ty
 // ── Root provider ────────────────────────────────────────────────────────────
 
 interface ImagePickerOpts
-	extends WithRefOpts,
+	extends
+		WithRefOpts,
 		StateProps<{
 			file: File | null;
 			fit: ImagePickerFit;
@@ -70,8 +71,7 @@ export class ImagePickerProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: ImagePickerProvider.ctx,
-			syncAttrs: true
+			context: ImagePickerProvider.ctx
 		});
 
 		// Object-URL lifecycle: create on file change, revoke the previous one
@@ -153,7 +153,7 @@ export class ImagePickerProvider {
 	/** Rotate the preview 90° clockwise. */
 	rotate(): void {
 		if (this.opts.disabled.current || !this.opts.file.current) return;
-		this.opts.rotation.current = (((this.opts.rotation.current + 90) % 360) as ImagePickerRotation);
+		this.opts.rotation.current = ((this.opts.rotation.current + 90) % 360) as ImagePickerRotation;
 		this.emitChange();
 		void this.runtime.trigger('handle-rotate');
 	}
@@ -200,8 +200,7 @@ export class ImagePickerPreviewProvider {
 				fit: () => this.provider.opts.fit.current,
 				// data-rotation values are strings ('0' / '90' / …) — stringify.
 				rotation: () => String(this.provider.opts.rotation.current)
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
@@ -227,8 +226,7 @@ export class ImagePickerToolbarProvider {
 		this.runtimePart = this.provider.runtime.part('toolbar', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -254,8 +252,7 @@ export class ImagePickerRotateProvider {
 		this.runtimePart = this.provider.runtime.part('rotate', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -297,8 +294,7 @@ export class ImagePickerRemoveProvider {
 		this.runtimePart = this.provider.runtime.part('remove', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/knob/knob-provider.svelte.ts b/src/uix/soma/components/knob/knob-provider.svelte.ts
index 6a73ec318..41d9174ea 100644
--- a/src/uix/soma/components/knob/knob-provider.svelte.ts
+++ b/src/uix/soma/components/knob/knob-provider.svelte.ts
@@ -114,8 +114,7 @@ export class KnobProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: KnobProvider.ctx,
-			syncAttrs: true
+			context: KnobProvider.ctx
 		});
 
 		// Radial pointer mechanics live in the shared gesture layer; this provider
@@ -273,7 +272,7 @@ export class KnobProvider {
 	}
 
 	// Root container props (`data-knob` + id). Sub-part attrs live on their own
-	// providers; syncAttrs applies the morfo-derived attrs to the ref directly.
+	// providers; the render bag resolves the morfo-derived attrs.
 	readonly props = $derived.by(() =>
 		this.runtimePart.assert({ ...this.runtimePart.props } as const)
 	);
@@ -299,7 +298,7 @@ export class KnobControlProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this
-			// no syncAttrs: render-bag path — we override aria-valuetext.
+			// Render-bag path — we override aria-valuetext in the getter below.
 		});
 	}
 
@@ -383,8 +382,7 @@ export class KnobIndicatorProvider {
 		this.runtimePart = this.provider.runtime.part('indicator', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 	readonly props = $derived.by(() =>
@@ -409,8 +407,7 @@ export class KnobLabelProvider {
 		this.runtimePart = this.provider.runtime.part('label', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 	readonly props = $derived.by(() =>
@@ -438,8 +435,7 @@ export class KnobValueTextProvider {
 		this.runtimePart = this.provider.runtime.part('value-text', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 	readonly props = $derived.by(() =>
@@ -460,8 +456,7 @@ export class KnobHiddenInputProvider {
 		this.runtimePart = this.provider.runtime.part('hidden-input', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 	readonly props = $derived.by(() =>
diff --git a/src/uix/soma/components/mask-field/mask-field-provider.svelte.test.ts b/src/uix/soma/components/mask-field/mask-field-provider.svelte.test.ts
index 59838c3c4..ff0ba6ba6 100644
--- a/src/uix/soma/components/mask-field/mask-field-provider.svelte.test.ts
+++ b/src/uix/soma/components/mask-field/mask-field-provider.svelte.test.ts
@@ -112,8 +112,9 @@ describe('MaskFieldProvider', () => {
 		});
 
 		await tick();
-		expect(root.getAttribute('data-empty')).toBe('');
-		expect(root.hasAttribute('data-complete')).toBe(false);
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.provider.props['data-empty']).toBe('');
+		expect('data-complete' in result.provider.props).toBe(false);
 
 		cleanup();
 		dom.dispose();
diff --git a/src/uix/soma/components/mask-field/mask-field-provider.svelte.ts b/src/uix/soma/components/mask-field/mask-field-provider.svelte.ts
index 75d24055a..e0c10b58e 100644
--- a/src/uix/soma/components/mask-field/mask-field-provider.svelte.ts
+++ b/src/uix/soma/components/mask-field/mask-field-provider.svelte.ts
@@ -95,8 +95,7 @@ export class MaskFieldProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: MaskFieldProvider.ctx,
-			syncAttrs: true
+			context: MaskFieldProvider.ctx
 		});
 
 		// Normalize an externally-set value into its masked form. Runs on mount
diff --git a/src/uix/soma/components/media-player/media-player-provider.svelte.test.ts b/src/uix/soma/components/media-player/media-player-provider.svelte.test.ts
index 262529916..230474375 100644
--- a/src/uix/soma/components/media-player/media-player-provider.svelte.test.ts
+++ b/src/uix/soma/components/media-player/media-player-provider.svelte.test.ts
@@ -229,14 +229,14 @@ describe('MediaPlayerProvider', () => {
 		expect(provider.paused).toBe(false);
 		expect(provider.started).toBe(true);
 
-		// Discrete flags reach the DOM through syncAttrs.
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
 		await tick();
-		expect(root.getAttribute('data-media')).toBe('video');
-		expect(root.hasAttribute('data-paused')).toBe(false);
+		expect(provider.props['data-media']).toBe('video');
+		expect('data-paused' in provider.props).toBe(false);
 
 		fake.emit('pause', { paused: true });
 		await tick();
-		expect(root.getAttribute('data-paused')).toBe('');
+		expect(provider.props['data-paused']).toBe('');
 
 		cleanup();
 		dom.dispose();
diff --git a/src/uix/soma/components/media-player/media-player-provider.svelte.ts b/src/uix/soma/components/media-player/media-player-provider.svelte.ts
index 426f94a78..86be4d3e8 100644
--- a/src/uix/soma/components/media-player/media-player-provider.svelte.ts
+++ b/src/uix/soma/components/media-player/media-player-provider.svelte.ts
@@ -97,7 +97,7 @@ interface MediaPlayerOpts
  *
  * - **Discrete** flags (paused / muted / buffering / fullscreen …) live in
  *   `$state`; the morfo declares each `data-*` with a `propRef` source so
- *   `syncAttrs` writes them — the provider never re-declares an attr.
+ *   the render bag resolves them — the provider never re-declares an attr.
  * - **Buffered** rides into the composed Slider as its `secondaryValue`
  *   (seconds, same domain as the scrubber) and the Slider's SecondaryRange
  *   paints it (G-2). Played progress is the composed Slider's value
@@ -146,7 +146,7 @@ export class MediaPlayerProvider {
 	 */
 	private skipToEnd = false;
 
-	// Discrete state — mirrored from the engine, drives `data-*` via syncAttrs.
+	// Discrete state — mirrored from the engine, drives `data-*` via the render bag.
 	paused = $state(true);
 	ended = $state(false);
 	seeking = $state(false);
@@ -232,8 +232,7 @@ export class MediaPlayerProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: MediaPlayerProvider.ctx,
-			syncAttrs: true
+			context: MediaPlayerProvider.ctx
 		});
 
 		// Reflect fullscreen state from the document (Esc, F11, the OS chrome).
diff --git a/src/uix/soma/components/meter/meter-provider.svelte.test.ts b/src/uix/soma/components/meter/meter-provider.svelte.test.ts
index 93ab12739..ddb0599f8 100644
--- a/src/uix/soma/components/meter/meter-provider.svelte.test.ts
+++ b/src/uix/soma/components/meter/meter-provider.svelte.test.ts
@@ -97,31 +97,34 @@ describe('MeterProvider', () => {
 		});
 
 		await tick();
-		expect(root.getAttribute('role')).toBe('meter');
-		expect(root.getAttribute('data-state')).toBe('optimum');
-		expect(root.getAttribute('data-value')).toBe('50');
-		expect(root.getAttribute('data-min')).toBe('0');
-		expect(root.getAttribute('data-max')).toBe('100');
-		expect(root.getAttribute('data-low')).toBe('30');
-		expect(root.getAttribute('data-high')).toBe('70');
-		expect(root.getAttribute('data-optimum')).toBe('50');
-		expect(root.getAttribute('aria-valuenow')).toBe('50');
-		expect(root.getAttribute('aria-valuetext')).toBe('50 / 100');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.provider.props).toMatchObject({
+			role: 'meter',
+			'data-state': 'optimum',
+			'data-value': 50,
+			'data-min': 0,
+			'data-max': 100,
+			'data-low': 30,
+			'data-high': 70,
+			'data-optimum': 50,
+			'aria-valuenow': 50,
+			'aria-valuetext': '50 / 100'
+		});
 		// Naming default: ships in the render bag (consumerWins, A-85).
 		expect(result.provider.props).toMatchObject({ 'aria-label': 'Meter' });
-		expect(indicatorEl.getAttribute('data-state')).toBe('optimum');
+		expect(result.indicator.props['data-state']).toBe('optimum');
 
 		opts.value.current = 20;
 		await tick();
 		expect(result.provider.state).toBe('below');
-		expect(root.getAttribute('data-state')).toBe('below');
-		expect(indicatorEl.getAttribute('data-state')).toBe('below');
+		expect(result.provider.props['data-state']).toBe('below');
+		expect(result.indicator.props['data-state']).toBe('below');
 
 		opts.value.current = 90;
 		await tick();
 		expect(result.provider.state).toBe('above');
-		expect(root.getAttribute('data-state')).toBe('above');
-		expect(indicatorEl.getAttribute('data-state')).toBe('above');
+		expect(result.provider.props['data-state']).toBe('above');
+		expect(result.indicator.props['data-state']).toBe('above');
 
 		cleanup();
 		dom.dispose();
@@ -157,9 +160,10 @@ describe('MeterProvider', () => {
 		// through dom.apply since A-85, which would make a DOM-only check pass
 		// trivially and stop guarding anything.
 		expect(provider.props).not.toHaveProperty('aria-label');
-		expect(root.hasAttribute('aria-label')).toBe(false);
-		expect(root.getAttribute('aria-labelledby')).toBe('meter-title');
-		expect(root.getAttribute('aria-valuetext')).toBe('Over target');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect('aria-label' in provider.props).toBe(false);
+		expect(provider.props['aria-labelledby']).toBe('meter-title');
+		expect(provider.props['aria-valuetext']).toBe('Over target');
 
 		cleanup();
 		dom.dispose();
diff --git a/src/uix/soma/components/meter/meter-provider.svelte.ts b/src/uix/soma/components/meter/meter-provider.svelte.ts
index 8a4194903..55dfb679e 100644
--- a/src/uix/soma/components/meter/meter-provider.svelte.ts
+++ b/src/uix/soma/components/meter/meter-provider.svelte.ts
@@ -6,7 +6,6 @@ import type { MeterZone } from './types';
 import { meterMorfo } from '../../../morfo/components/meter';
 import type { SomaRuntime, SomaRuntimePart } from '../../runtime.svelte';
 
-
 function computeZone(value: number, low: number, high: number): MeterZone {
 	if (value < low) return 'below';
 	if (value > high) return 'above';
@@ -68,8 +67,7 @@ export class MeterProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: MeterProvider.ctx,
-			syncAttrs: true
+			context: MeterProvider.ctx
 		});
 	}
 
@@ -137,8 +135,7 @@ export class MeterIndicatorProvider {
 			states: {
 				optimum: () => this.provider.state
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/nav-tree/nav-tree-provider.svelte.ts b/src/uix/soma/components/nav-tree/nav-tree-provider.svelte.ts
index 17d8fa7a2..d81bb1a3e 100644
--- a/src/uix/soma/components/nav-tree/nav-tree-provider.svelte.ts
+++ b/src/uix/soma/components/nav-tree/nav-tree-provider.svelte.ts
@@ -86,8 +86,7 @@ export class NavTreeProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: NavTreeProvider.ctx,
-			syncAttrs: true
+			context: NavTreeProvider.ctx
 		});
 		this.listPart = this.runtime.part('list', {
 			id: readableActive(() => `${opts.id.current}-list`)
@@ -205,7 +204,7 @@ export class NavTreeProvider {
 
 	readonly providerProps = $derived.by(() =>
 		this.providerPart.assert({
-			...this.providerPart.props,
+			...this.providerPart.props
 			// The recipe selects with `:dir(rtl)`, which reads the RESOLVED direction,
 			// so an asserted `dir` must reach the DOM or the paint would lag the prop.
 			// Raw, not `resolvedDir`: no assertion means no attribute (direction contract).
diff --git a/src/uix/soma/components/number-field/number-field-provider.svelte.ts b/src/uix/soma/components/number-field/number-field-provider.svelte.ts
index 11da7f4bd..f4a20eff1 100644
--- a/src/uix/soma/components/number-field/number-field-provider.svelte.ts
+++ b/src/uix/soma/components/number-field/number-field-provider.svelte.ts
@@ -149,7 +149,6 @@ interface NumberFieldOpts
 		}> {}
 
 export class NumberFieldProvider {
-
 	readonly opts: NumberFieldOpts;
 	readonly runtimePart: SomaRuntimePart<typeof numberFieldMorfo, 'provider'>;
 	readonly soma: Soma;
@@ -219,8 +218,7 @@ export class NumberFieldProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: NumberFieldProvider.ctx,
-			syncAttrs: true
+			context: NumberFieldProvider.ctx
 		});
 
 		this.locale = readableActive(() => opts.locale.current ?? this.soma.langs.getLocale() ?? 'en');
@@ -552,7 +550,7 @@ export class NumberFieldProvider {
 
 	readonly props = $derived.by(() =>
 		this.runtimePart.assert({
-			...this.runtimePart.props,
+			...this.runtimePart.props
 			// The attribute carries the RAW assertion, never the resolved value:
 			// omitted when nobody asserted a direction, so the element inherits
 			// instead of forcing `ltr`. `this.dir` stays for the maths.
diff --git a/src/uix/soma/components/pagination/pagination-provider.svelte.test.ts b/src/uix/soma/components/pagination/pagination-provider.svelte.test.ts
index 01554823d..3226dbf4c 100644
--- a/src/uix/soma/components/pagination/pagination-provider.svelte.test.ts
+++ b/src/uix/soma/components/pagination/pagination-provider.svelte.test.ts
@@ -188,11 +188,13 @@ describe('PaginationProvider', () => {
 		});
 
 		await tick();
-		// Root + ellipsis keep `syncAttrs: true`, so their morfo attrs are still
-		// applied imperatively to the bare element.
-		expect(root.getAttribute('role')).toBe('navigation');
-		expect(ellipsisEl.getAttribute('data-position')).toBe('end');
-		expect(ellipsisEl.getAttribute('aria-hidden')).toBe('true');
+		// Root + ellipsis compose through the render bag too (fase C2c retired
+		// the syncAttrs effect); this test renders nothing, so assert the bags.
+		expect(result.provider.props).toMatchObject({ role: 'navigation' });
+		expect(result.ellipsis.props).toMatchObject({
+			'data-position': 'end',
+			'aria-hidden': 'true'
+		});
 		// Triggers + item now compose their morfo attrs through the render bag
 		// (no `syncAttrs`); a Svelte component spreads `props` onto the element in
 		// production, but this test never renders one — assert the props object.
@@ -246,7 +248,7 @@ describe('PaginationProvider', () => {
 				ref: state<HTMLElement | null>(itemEl),
 				value: state(2)
 			});
-			return { next, item };
+			return { provider, next, item };
 		});
 
 		expect(result.next.props.disabled).toBe(true);
@@ -256,8 +258,8 @@ describe('PaginationProvider', () => {
 		expect(opts.page.current).toBe(1);
 
 		await tick();
-		// Root keeps `syncAttrs: true` → still applied to the bare element.
-		expect(root.getAttribute('data-disabled')).toBe('');
+		// Root composes through the render bag too (fase C2c) — assert the bag.
+		expect(result.provider.props).toMatchObject({ 'data-disabled': '' });
 		// next-trigger + item now project data-disabled via `the render bag`
 		// (no `syncAttrs`); assert the props object instead of the bare element.
 		expect(result.next.props).toMatchObject({ 'data-disabled': '' });
diff --git a/src/uix/soma/components/pagination/pagination-provider.svelte.ts b/src/uix/soma/components/pagination/pagination-provider.svelte.ts
index 085f5c318..e83cd997d 100644
--- a/src/uix/soma/components/pagination/pagination-provider.svelte.ts
+++ b/src/uix/soma/components/pagination/pagination-provider.svelte.ts
@@ -116,8 +116,7 @@ export class PaginationProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: PaginationProvider.ctx,
-			syncAttrs: true
+			context: PaginationProvider.ctx
 		});
 
 		// Clamp page to valid range reactively (like Ark-UI/Zag.js)
@@ -521,8 +520,7 @@ export class PaginationEllipsisProvider {
 			props: {
 				position: () => this.opts.position.current
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/palabras/palabras-provider.svelte.test.ts b/src/uix/soma/components/palabras/palabras-provider.svelte.test.ts
index c6c1efd9f..11551d315 100644
--- a/src/uix/soma/components/palabras/palabras-provider.svelte.test.ts
+++ b/src/uix/soma/components/palabras/palabras-provider.svelte.test.ts
@@ -200,10 +200,11 @@ describe('PalabrasProvider', () => {
 		expect(result.hidden.props.value).toContain('hello');
 
 		await tick();
-		expect(root.getAttribute('data-required')).toBe('');
-		expect(root.getAttribute('data-invalid')).toBe('');
-		expect(root.hasAttribute('data-empty')).toBe(false);
-		expect(contentEl.getAttribute('data-block')).toBe('paragraph');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.provider.props['data-required']).toBe('');
+		expect(result.provider.props['data-invalid']).toBe('');
+		expect('data-empty' in result.provider.props).toBe(false);
+		expect(result.content.props['data-block']).toBe('paragraph');
 
 		cleanup();
 		dom.dispose();
@@ -1131,16 +1132,17 @@ describe('PalabrasProvider', () => {
 		});
 		expect(result.commit.props['aria-pressed']).toBeUndefined();
 		await tick();
-		expect(buttonEl.getAttribute('data-state')).toBe('off');
-		expect(buttonEl.getAttribute('aria-pressed')).toBe('false');
-		expect(commitEl.hasAttribute('aria-pressed')).toBe(false);
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.bold.props['data-state']).toBe('off');
+		expect(result.bold.props['aria-pressed']).toBe(false);
+		expect('aria-pressed' in result.commit.runtimePart.props).toBe(false);
 
 		result.bold.props.onclick({ currentTarget: buttonEl } as never);
 		expect(result.provider.activeMarks).toEqual(['bold']);
 		expect(result.bold.props['aria-pressed']).toBe(true);
 		await tick();
-		expect(buttonEl.getAttribute('data-state')).toBe('on');
-		expect(buttonEl.getAttribute('aria-pressed')).toBe('true');
+		expect(result.bold.props['data-state']).toBe('on');
+		expect(result.bold.props['aria-pressed']).toBe(true);
 
 		cleanup();
 		dom.dispose();
@@ -2377,9 +2379,7 @@ describe('PalabrasProvider', () => {
 		// Live: a structural edit updates the derived outline + counts.
 		result.applyCommand({
 			type: 'insertBlocks',
-			blocks: [
-				{ type: 'heading', level: 3, children: [createText('Nuevo tramo')] } as never
-			],
+			blocks: [{ type: 'heading', level: 3, children: [createText('Nuevo tramo')] } as never],
 			at: 3
 		});
 		expect(result.wordCount).toBe(8);
@@ -2709,7 +2709,10 @@ describe('PalabrasProvider · multilingual (F-A)', () => {
 		const root = document.createElement('div');
 		document.body.append(root);
 		// The folded doc carries `doc.languages`; the `languages` PROP is left unset.
-		const opts = palabrasOpts(root, foldPalabrasLanguages({ es: doc('Hola'), en: doc('Hello') }, 'es'));
+		const opts = palabrasOpts(
+			root,
+			foldPalabrasLanguages({ es: doc('Hola'), en: doc('Hello') }, 'es')
+		);
 		const { result, cleanup } = withEffectRoot(() => {
 			const provider = PalabrasProvider.create(opts);
 			vi.spyOn(PalabrasProvider, 'require').mockReturnValue(provider);
@@ -2758,10 +2761,10 @@ describe('PalabrasProvider · multilingual (F-A)', () => {
 	});
 
 	it('an external value-write carrying a DIFFERENT activeLang is honored, not reverted', () => {
-		const { provider, opts, cleanup, dom } = multiProvider(
-			{ es: doc('Hola'), en: doc('Hello') },
-			['es', 'en']
-		);
+		const { provider, opts, cleanup, dom } = multiProvider({ es: doc('Hola'), en: doc('Hello') }, [
+			'es',
+			'en'
+		]);
 		expect(provider.activeLang).toBe('es');
 		// Simulate loading a doc last edited in English: an external write whose
 		// activeLang is 'en' and whose children hold English. The consumer binds
diff --git a/src/uix/soma/components/palabras/palabras-provider.svelte.ts b/src/uix/soma/components/palabras/palabras-provider.svelte.ts
index 034916f4a..5fd4adfbe 100644
--- a/src/uix/soma/components/palabras/palabras-provider.svelte.ts
+++ b/src/uix/soma/components/palabras/palabras-provider.svelte.ts
@@ -126,7 +126,9 @@ interface PalabrasOpts
 			ariaLabel: string | undefined;
 			onValueChange: OnChangeFn<PalabrasDocument> | undefined;
 			onSelectionChange: OnChangeFn<PalabrasSelection | null> | undefined;
-			onValueCommit: ((document: PalabrasDocument, reason: PalabrasCommitReason) => void) | undefined;
+			onValueCommit:
+				| ((document: PalabrasDocument, reason: PalabrasCommitReason) => void)
+				| undefined;
 			onUploadImage: PalabrasOnUploadImage | undefined;
 			insertableBlocks: readonly string[] | undefined;
 			languages: readonly LangSpec[] | undefined;
@@ -138,7 +140,8 @@ interface PalabrasContentOpts extends WithRefOpts {}
 interface PalabrasPlaceholderOpts extends WithRefOpts {}
 interface PalabrasToolbarOpts extends WithRefOpts {}
 interface PalabrasToolbarGroupOpts extends WithRefOpts {}
-interface PalabrasBubbleMenuOpts extends WithRefOpts, ActiveProps<{ side: PalabrasBubbleMenuSide }> {}
+interface PalabrasBubbleMenuOpts
+	extends WithRefOpts, ActiveProps<{ side: PalabrasBubbleMenuSide }> {}
 interface PalabrasSlashMenuOpts extends WithRefOpts {}
 interface PalabrasCommandButtonOpts
 	extends
@@ -159,9 +162,7 @@ interface PalabrasFindReplaceOpts extends WithRefOpts {}
 interface PalabrasHiddenInputOpts extends WithRefOpts {}
 interface PalabrasStatusOpts extends WithRefOpts {}
 interface PalabrasDrawerOpts
-	extends WithRefOpts,
-		StateProps<{ open: boolean }>,
-		ActiveProps<{ disabled: boolean }> {}
+	extends WithRefOpts, StateProps<{ open: boolean }>, ActiveProps<{ disabled: boolean }> {}
 type PalabrasSelectionSyncSource =
 	| 'selectionchange'
 	| 'pointer'
@@ -419,8 +420,7 @@ export class PalabrasProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: PalabrasProvider.ctx,
-			syncAttrs: true
+			context: PalabrasProvider.ctx
 		});
 
 		if (this.field) this.field.inputId.current = opts.contentId.current;
@@ -2083,8 +2083,7 @@ export class PalabrasProvider {
 		this.ensureCaret();
 		const sel = this.selection;
 		const doc = this.history.present.document;
-		const currentIdx =
-			sel?.anchor.path[0] ?? Math.max(0, doc.children.length - 1);
+		const currentIdx = sel?.anchor.path[0] ?? Math.max(0, doc.children.length - 1);
 		const current = doc.children[currentIdx];
 
 		// Empty-paragraph heuristic — match what the slash menu treats
@@ -2102,10 +2101,8 @@ export class PalabrasProvider {
 		if (id === 'table') return this.applyCommand({ type: 'insertTable' });
 		if (id === 'unordered-list')
 			return this.applyCommand({ type: 'toggleList', kind: 'unordered' });
-		if (id === 'ordered-list')
-			return this.applyCommand({ type: 'toggleList', kind: 'ordered' });
-		if (id === 'check-list')
-			return this.applyCommand({ type: 'toggleList', kind: 'check' });
+		if (id === 'ordered-list') return this.applyCommand({ type: 'toggleList', kind: 'ordered' });
+		if (id === 'check-list') return this.applyCommand({ type: 'toggleList', kind: 'check' });
 		if (id === 'image') {
 			const node = this.opts.ref.current;
 			const win = node?.ownerDocument?.defaultView ?? undefined;
@@ -2329,7 +2326,10 @@ export class PalabrasProvider {
 		// The structural `samePalabrasDocument` below is an O(document) deep walk —
 		// catastrophic per keystroke with large base64 data-URLs — so only reach it
 		// when the external value genuinely differs (an external write).
-		if (externalDocument !== this.publishedExternal && !samePalabrasDocument(externalDocument, current.document)) {
+		if (
+			externalDocument !== this.publishedExternal &&
+			!samePalabrasDocument(externalDocument, current.document)
+		) {
 			const nextState = createState(externalDocument, externalSelection);
 			if (!samePalabrasDocument(nextState.document, current.document)) {
 				const limit = this.history.limit;
@@ -2472,10 +2472,7 @@ export class PalabrasProvider {
 				// Scope to the block containing the current selection (or
 				// the explicitly-selected atomic block via image float
 				// bar). No-op when neither is set.
-				const idx =
-					this.selectedBlockIndex ??
-					this.opts.selection.current?.anchor.path[0] ??
-					-1;
+				const idx = this.selectedBlockIndex ?? this.opts.selection.current?.anchor.path[0] ?? -1;
 				if (idx < 0) return undefined;
 				return { type: 'deleteBlock', blockIndex: idx };
 			}
@@ -2546,8 +2543,7 @@ export class PalabrasContentProvider {
 			owner: this,
 			onRefChange: (el) => {
 				this.provider.setContentRef(el);
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
@@ -2609,8 +2605,7 @@ export class PalabrasPlaceholderProvider {
 		this.runtimePart = this.provider.runtime.part('placeholder', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -2644,8 +2639,7 @@ export class PalabrasToolbarProvider {
 			owner: this,
 			props: {
 				disabled: () => this.provider.isDisabled
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
@@ -2673,8 +2667,7 @@ export class PalabrasToolbarGroupProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			props: {},
-			syncAttrs: true
+			props: {}
 		});
 	}
 
@@ -2709,8 +2702,7 @@ export class PalabrasBubbleMenuProvider {
 				selectionKind: () => this.provider.selectionKind,
 				side: () => this.opts.side.current,
 				disabled: () => this.provider.isDisabled
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
@@ -2809,8 +2801,7 @@ export class PalabrasSlashMenuProvider {
 				activeIndex: () => this.provider.slashMenuActiveIndex,
 				disabled: () => this.provider.isDisabled,
 				readonly: () => this.provider.isReadonly
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
@@ -2903,8 +2894,7 @@ export class PalabrasCommandButtonProvider {
 				active: () => this.isActive,
 				disabled: () => this.isDisabled,
 				toggle: () => isToggleCommand(this.opts.command.current)
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
@@ -3068,8 +3058,7 @@ export class PalabrasLinkEditorProvider {
 				activeLink: () => Boolean(this.selectedLink),
 				disabled: () => this.provider.isDisabled || this.provider.isReadonly,
 				invalid: () => Boolean(this.error)
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
@@ -3174,8 +3163,7 @@ export class PalabrasFindReplaceProvider {
 				disabled: () => this.provider.isDisabled,
 				readonly: () => this.provider.isReadonly,
 				hasMatches: () => this.provider.hasFindMatches
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
@@ -3269,8 +3257,7 @@ export class PalabrasStatusProvider {
 			owner: this,
 			props: {
 				status: () => this.provider.status
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
@@ -3329,8 +3316,7 @@ export class PalabrasDrawerProvider {
 				mode: () => this.mode,
 				open: () => this.opts.open.current,
 				disabled: () => this.opts.disabled.current || this.provider.isDisabled
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
@@ -3360,8 +3346,7 @@ export class PalabrasDrawerProvider {
 		// solo se muestran los constructores; cuando ya tiene contenido,
 		// las opciones del objeto".
 		const currentIdx = sel?.anchor.path[0] ?? this.provider.selectedBlockIndex ?? -1;
-		const currentNode =
-			currentIdx >= 0 ? this.provider.document.children[currentIdx] : undefined;
+		const currentNode = currentIdx >= 0 ? this.provider.document.children[currentIdx] : undefined;
 		const isEmptyTextBlock = isEmptyEditableTextBlock(currentNode);
 
 		// Atomic blocks (no inline format, no parent scopes)
@@ -3470,8 +3455,7 @@ export class PalabrasDrawerProvider {
 			role: 'complementary' as const,
 			'data-palabras-drawer-mode': this.mode,
 			'data-open': this.opts.open.current ? '' : undefined,
-			'data-disabled':
-				this.opts.disabled.current || this.provider.isDisabled ? '' : undefined
+			'data-disabled': this.opts.disabled.current || this.provider.isDisabled ? '' : undefined
 		} as const)
 	);
 }
@@ -3596,12 +3580,7 @@ function isEmptyEditableTextBlock(block: unknown): boolean {
 		language?: string;
 		children?: readonly { type?: string; text?: string }[];
 	};
-	if (
-		b.type !== 'paragraph' &&
-		b.type !== 'heading' &&
-		b.type !== 'quote' &&
-		b.type !== 'code'
-	) {
+	if (b.type !== 'paragraph' && b.type !== 'heading' && b.type !== 'quote' && b.type !== 'code') {
 		return false;
 	}
 	// A code block with a language already carries intent — even an
@@ -3858,7 +3837,8 @@ function imageStatusSig(block: PalabrasBlock, status: ReadonlyMap<string, string
 			return;
 		}
 		if (b.type === 'table') {
-			for (const row of b.rows) for (const cell of row.cells) for (const child of cell.children) visit(child);
+			for (const row of b.rows)
+				for (const cell of row.cells) for (const child of cell.children) visit(child);
 		}
 	};
 	visit(block);
diff --git a/src/uix/soma/components/password-field/password-field-provider.svelte.ts b/src/uix/soma/components/password-field/password-field-provider.svelte.ts
index c70deebda..0047e98fb 100644
--- a/src/uix/soma/components/password-field/password-field-provider.svelte.ts
+++ b/src/uix/soma/components/password-field/password-field-provider.svelte.ts
@@ -1,11 +1,6 @@
 import { context, type WithRefOpts } from '../../provider';
 import { state, type ActiveProps, type StateProps } from '$libs/reactive';
-import type {
-	OnChangeFn,
-	SomaFocusEvent,
-	SomaInputEvent,
-	SomaKeyboardEvent
-} from '../../types';
+import type { OnChangeFn, SomaFocusEvent, SomaInputEvent, SomaKeyboardEvent } from '../../types';
 import { KEYS } from '../../keyboard';
 import { Soma } from '../../core/soma.svelte';
 import { FieldProvider } from '../field';
@@ -131,8 +126,7 @@ export class PasswordFieldProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: PasswordFieldProvider.ctx,
-			syncAttrs: true
+			context: PasswordFieldProvider.ctx
 		});
 
 		// Register Input id with parent Field so `Field.Label`'s `for=` lands.
@@ -312,10 +306,9 @@ export class PasswordFieldInputProvider {
 	readonly describedBy = $derived.by(() => {
 		const field = this.provider.field;
 		if (!field) return undefined;
-		const ids = [
-			field.helperId.current,
-			field.isInvalid ? field.errorId.current : ''
-		].filter(Boolean);
+		const ids = [field.helperId.current, field.isInvalid ? field.errorId.current : ''].filter(
+			Boolean
+		);
 		return ids.length > 0 ? ids.join(' ') : undefined;
 	});
 
@@ -523,8 +516,7 @@ export class PasswordFieldStrengthMeterProvider {
 	readonly snippetProps = $derived.by(() => ({
 		strength: this.clampedStrength,
 		label: '',
-		warnings:
-			this.opts.strength.current !== undefined ? [] : this.provider.derivedWarnings
+		warnings: this.opts.strength.current !== undefined ? [] : this.provider.derivedWarnings
 	}));
 
 	readonly props = $derived.by(() =>
diff --git a/src/uix/soma/components/popover/popover-provider.svelte.test.ts b/src/uix/soma/components/popover/popover-provider.svelte.test.ts
index e0396c0e9..c4d8c3bcb 100644
--- a/src/uix/soma/components/popover/popover-provider.svelte.test.ts
+++ b/src/uix/soma/components/popover/popover-provider.svelte.test.ts
@@ -97,8 +97,7 @@ describe('PopoverProvider', () => {
 			p.contentId.current = 'popover-content';
 			p.runtime.part('content', {
 				id: state('popover-content'),
-				ref: state<HTMLElement | null>(target),
-				syncAttrs: true
+				ref: state<HTMLElement | null>(target)
 			});
 			return p;
 		});
@@ -134,7 +133,7 @@ describe('PopoverProvider', () => {
 		const description = document.createElement('div');
 		document.body.append(trigger, content, title, description);
 
-		const { cleanup } = withEffectRoot(() => {
+		const { result: parts, cleanup } = withEffectRoot(() => {
 			const p = PopoverProvider.create(opts);
 			p.triggerId.current = 'popover-trigger';
 			p.contentId.current = 'popover-content';
@@ -142,35 +141,34 @@ describe('PopoverProvider', () => {
 			p.descriptionId.current = 'popover-description';
 			p.runtime.part('trigger', {
 				id: state('popover-trigger'),
-				ref: state<HTMLElement | null>(trigger),
-				syncAttrs: true
+				ref: state<HTMLElement | null>(trigger)
 			});
-			p.runtime.part('content', {
+			const contentPart = p.runtime.part('content', {
 				id: state('popover-content'),
-				ref: state<HTMLElement | null>(content),
-				syncAttrs: true
+				ref: state<HTMLElement | null>(content)
 			});
-			p.runtime.part('title', {
+			const titlePart = p.runtime.part('title', {
 				id: state('popover-title'),
 				ref: state<HTMLElement | null>(title),
-				props: { level: () => 3 },
-				syncAttrs: true
+				props: { level: () => 3 }
 			});
 			p.runtime.part('description', {
 				id: state('popover-description'),
-				ref: state<HTMLElement | null>(description),
-				syncAttrs: true
+				ref: state<HTMLElement | null>(description)
 			});
-			return p;
+			return { contentPart, titlePart };
 		});
 
 		await Promise.resolve();
 		await Promise.resolve();
 
-		expect(content.getAttribute('aria-labelledby')).toBe('popover-title');
-		expect(content.getAttribute('aria-describedby')).toBe('popover-description');
-		expect(title.getAttribute('role')).toBe('heading');
-		expect(title.getAttribute('aria-level')).toBe('3');
+		// The labels travel in the render bag (fase C2c retired the syncAttrs
+		// effect); this test renders nothing, so assert the bags directly.
+		expect(parts.contentPart.props).toMatchObject({
+			'aria-labelledby': 'popover-title',
+			'aria-describedby': 'popover-description'
+		});
+		expect(parts.titlePart.props).toMatchObject({ role: 'heading', 'aria-level': 3 });
 
 		cleanup();
 		timers.dispose();
diff --git a/src/uix/soma/components/popover/popover-provider.svelte.ts b/src/uix/soma/components/popover/popover-provider.svelte.ts
index 833231007..998ad8172 100644
--- a/src/uix/soma/components/popover/popover-provider.svelte.ts
+++ b/src/uix/soma/components/popover/popover-provider.svelte.ts
@@ -184,8 +184,7 @@ export class PopoverProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: PopoverProvider.ctx,
-			syncAttrs: true
+			context: PopoverProvider.ctx
 		});
 
 		$effect(() => {
@@ -251,10 +250,7 @@ export class PopoverProvider {
 		return this.triggerClose(DISMISS_CAUSES[action], opts);
 	}
 
-	private async triggerClose(
-		cause: DismissCause,
-		opts: { message?: string } = {}
-	): Promise<void> {
+	private async triggerClose(cause: DismissCause, opts: { message?: string } = {}): Promise<void> {
 		// Imperative prewrite of `data-last-action` since the morfo's
 		// polymorphic `close` can't bind a single `prewrite` per call. It is
 		// CONTENT's exit-cause tint (the eidos recipe reads it there); the
@@ -331,19 +327,22 @@ export class PopoverProvider {
 
 // ── Trigger ─────────────────────────────────────────────────────────────────
 
-interface PopoverTriggerOpts extends WithRefOpts, ActiveProps<{
-	openOnHover: boolean;
-	openDelay: number;
-	closeDelay: number;
-	/**
-	 * When true the trigger is inert: click / keyboard / hover neither toggle the
-	 * popover nor emit the `open` signal. Stays focusable — the consumer adds
-	 * the native `disabled` attr separately if it wants to drop the tab stop.
-	 * Optional; defaults to interactive. Used by field-overlay triggers (pickers)
-	 * to honour `disabled` / `readonly` without losing focusability.
-	 */
-	disabled?: boolean;
-}> {}
+interface PopoverTriggerOpts
+	extends
+		WithRefOpts,
+		ActiveProps<{
+			openOnHover: boolean;
+			openDelay: number;
+			closeDelay: number;
+			/**
+			 * When true the trigger is inert: click / keyboard / hover neither toggle the
+			 * popover nor emit the `open` signal. Stays focusable — the consumer adds
+			 * the native `disabled` attr separately if it wants to drop the tab stop.
+			 * Optional; defaults to interactive. Used by field-overlay triggers (pickers)
+			 * to honour `disabled` / `readonly` without losing focusability.
+			 */
+			disabled?: boolean;
+		}> {}
 
 export class PopoverTriggerProvider {
 	static create(opts: PopoverTriggerOpts) {
@@ -362,8 +361,7 @@ export class PopoverTriggerProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			onRefChange: (el) => this.provider.setTriggerRef(el),
-			syncAttrs: true
+			onRefChange: (el) => this.provider.setTriggerRef(el)
 		});
 
 		// Register as floating anchor
@@ -445,40 +443,43 @@ export class PopoverTriggerProvider {
 
 // ── Content ─────────────────────────────────────────────────────────────────
 
-interface PopoverContentOpts extends WithRefOpts, ActiveProps<{
-	side: Side;
-	sideOffset: number;
-	align: Align;
-	alignOffset: number;
-	arrowPadding: number;
-	avoidCollisions: boolean | 'flip';
-	collisionBoundary: Arrayable<Boundary>;
-	collisionPadding: number | Partial<Record<Side, number>>;
-	sticky: 'partial' | 'always';
-	hideWhenDetached: boolean;
-	updatePositionStrategy: 'optimized' | 'always';
-	strategy: 'fixed' | 'absolute';
-	customAnchor: string | HTMLElement | null;
-	// `trapFocus` / `preventScroll` default to `modal` when omitted —
-	// see PopoverContentProvider constructor for the resolution.
-	trapFocus: boolean | undefined;
-	loop: boolean;
-	preventScroll: boolean | undefined;
-	restoreScrollDelay: number;
-	onOpenAutoFocus: (e: Event) => void;
-	onCloseAutoFocus: (e: Event) => void;
-	onEscapeKeydown: (e: KeyboardEvent) => void;
-	escapeKeydownBehavior: DismissalBehavior | undefined;
-	onInteractOutside: (e: PointerEvent) => void;
-	interactOutsideBehavior: DismissalBehavior | undefined;
-	onFocusOutside: (e: FocusEvent) => void;
-	onPlaced: () => void;
-	/** `undefined` = nobody asserted a direction. Forwarded to the Floating
-	 *  layer, which stamps it on the portalled wrapper — omitted means inherit
-	 *  from the portal host instead of forcing `ltr`. */
-	dir: Direction | undefined;
-	style: StyleProperties | null | undefined | string;
-}> {}
+interface PopoverContentOpts
+	extends
+		WithRefOpts,
+		ActiveProps<{
+			side: Side;
+			sideOffset: number;
+			align: Align;
+			alignOffset: number;
+			arrowPadding: number;
+			avoidCollisions: boolean | 'flip';
+			collisionBoundary: Arrayable<Boundary>;
+			collisionPadding: number | Partial<Record<Side, number>>;
+			sticky: 'partial' | 'always';
+			hideWhenDetached: boolean;
+			updatePositionStrategy: 'optimized' | 'always';
+			strategy: 'fixed' | 'absolute';
+			customAnchor: string | HTMLElement | null;
+			// `trapFocus` / `preventScroll` default to `modal` when omitted —
+			// see PopoverContentProvider constructor for the resolution.
+			trapFocus: boolean | undefined;
+			loop: boolean;
+			preventScroll: boolean | undefined;
+			restoreScrollDelay: number;
+			onOpenAutoFocus: (e: Event) => void;
+			onCloseAutoFocus: (e: Event) => void;
+			onEscapeKeydown: (e: KeyboardEvent) => void;
+			escapeKeydownBehavior: DismissalBehavior | undefined;
+			onInteractOutside: (e: PointerEvent) => void;
+			interactOutsideBehavior: DismissalBehavior | undefined;
+			onFocusOutside: (e: FocusEvent) => void;
+			onPlaced: () => void;
+			/** `undefined` = nobody asserted a direction. Forwarded to the Floating
+			 *  layer, which stamps it on the portalled wrapper — omitted means inherit
+			 *  from the portal host instead of forcing `ltr`. */
+			dir: Direction | undefined;
+			style: StyleProperties | null | undefined | string;
+		}> {}
 
 export class PopoverContentProvider {
 	static create(opts: PopoverContentOpts) {
@@ -505,8 +506,7 @@ export class PopoverContentProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			onRefChange: (el) => this.provider.setContentRef(el),
-			syncAttrs: true
+			onRefChange: (el) => this.provider.setContentRef(el)
 		});
 
 		// Floating positioning
@@ -645,8 +645,7 @@ export class PopoverTitleProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			props: { level: () => this.opts.level.current },
-			syncAttrs: true
+			props: { level: () => this.opts.level.current }
 		});
 	}
 
@@ -675,8 +674,7 @@ export class PopoverDescriptionProvider {
 		this.runtimePart = this.provider.runtime.part('description', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -705,8 +703,7 @@ export class PopoverArrowProvider {
 		this.runtimePart = this.provider.runtime.part('arrow', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 		this.floatingArrow = FloatingArrow.create(opts);
 	}
@@ -738,8 +735,7 @@ export class PopoverCloseProvider {
 		this.runtimePart = this.provider.runtime.part('close', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -777,8 +773,7 @@ export class PopoverAnchorProvider {
 		this.runtimePart = this.provider.runtime.part('anchor', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 
 		// Override the floating anchor to use this element instead of trigger
@@ -813,8 +808,7 @@ export class PopoverOverlayProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			onRefChange: (el) => this.provider.setOverlayRef(el),
-			syncAttrs: true
+			onRefChange: (el) => this.provider.setOverlayRef(el)
 		});
 	}
 
diff --git a/src/uix/soma/components/progress/progress-provider.svelte.test.ts b/src/uix/soma/components/progress/progress-provider.svelte.test.ts
index 951202286..53b268f79 100644
--- a/src/uix/soma/components/progress/progress-provider.svelte.test.ts
+++ b/src/uix/soma/components/progress/progress-provider.svelte.test.ts
@@ -97,17 +97,20 @@ describe('ProgressProvider', () => {
 		});
 
 		await tick();
-		expect(root.getAttribute('role')).toBe('progressbar');
-		expect(root.getAttribute('data-state')).toBe('loading');
-		expect(root.getAttribute('data-value')).toBe('40');
-		expect(root.getAttribute('data-min')).toBe('0');
-		expect(root.getAttribute('data-max')).toBe('100');
-		expect(root.getAttribute('data-orientation')).toBe('horizontal');
-		expect(root.getAttribute('aria-valuenow')).toBe('40');
-		expect(root.getAttribute('aria-valuetext')).toBe('40 / 100');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.provider.props).toMatchObject({
+			role: 'progressbar',
+			'data-state': 'loading',
+			'data-value': 40,
+			'data-min': 0,
+			'data-max': 100,
+			'data-orientation': 'horizontal',
+			'aria-valuenow': 40,
+			'aria-valuetext': '40 / 100'
+		});
 		// Naming default: ships in the render bag (consumerWins, A-85).
 		expect(result.provider.props).toMatchObject({ 'aria-label': 'Loading' });
-		expect(indicatorEl.getAttribute('data-state')).toBe('loading');
+		expect(result.indicator.props['data-state']).toBe('loading');
 
 		opts.value.current = null;
 		await tick();
@@ -115,16 +118,16 @@ describe('ProgressProvider', () => {
 		expect(result.provider.props.style).toEqual({
 			'--_progress-value-pct': '0'
 		});
-		expect(root.getAttribute('data-state')).toBe('indeterminate');
-		expect(root.hasAttribute('data-value')).toBe(false);
-		expect(root.hasAttribute('aria-valuenow')).toBe(false);
-		expect(indicatorEl.getAttribute('data-state')).toBe('indeterminate');
+		expect(result.provider.props['data-state']).toBe('indeterminate');
+		expect('data-value' in result.provider.props).toBe(false);
+		expect('aria-valuenow' in result.provider.props).toBe(false);
+		expect(result.indicator.props['data-state']).toBe('indeterminate');
 
 		opts.value.current = 100;
 		await tick();
 		expect(result.provider.state).toBe('loaded');
-		expect(root.getAttribute('data-state')).toBe('loaded');
-		expect(indicatorEl.getAttribute('data-state')).toBe('loaded');
+		expect(result.provider.props['data-state']).toBe('loaded');
+		expect(result.indicator.props['data-state']).toBe('loaded');
 
 		cleanup();
 		dom.dispose();
@@ -146,9 +149,10 @@ describe('ProgressProvider', () => {
 		// through dom.apply since A-85, which would make a DOM-only check pass
 		// trivially and stop guarding anything.
 		expect(provider.props).not.toHaveProperty('aria-label');
-		expect(root.hasAttribute('aria-label')).toBe(false);
-		expect(root.getAttribute('aria-labelledby')).toBe('progress-title');
-		expect(root.getAttribute('aria-valuetext')).toBe('Forty percent');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect('aria-label' in provider.props).toBe(false);
+		expect(provider.props['aria-labelledby']).toBe('progress-title');
+		expect(provider.props['aria-valuetext']).toBe('Forty percent');
 
 		cleanup();
 		dom.dispose();
@@ -182,9 +186,10 @@ describe('ProgressProvider', () => {
 		// The internal `Progress.Label` names the bar by reference, so the morfo
 		// condition drops the default from the bag too — not just from the DOM.
 		expect(result.provider.props).not.toHaveProperty('aria-label');
-		expect(root.hasAttribute('aria-label')).toBe(false);
-		expect(root.getAttribute('aria-labelledby')).toBe('progress-label');
-		expect(root.getAttribute('data-orientation')).toBe('vertical');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect('aria-label' in result.provider.props).toBe(false);
+		expect(result.provider.props['aria-labelledby']).toBe('progress-label');
+		expect(result.provider.props['data-orientation']).toBe('vertical');
 		expect(result.label.props).toMatchObject({
 			id: 'progress-label',
 			'data-progress-label': ''
diff --git a/src/uix/soma/components/progress/progress-provider.svelte.ts b/src/uix/soma/components/progress/progress-provider.svelte.ts
index 777b54f63..83afda257 100644
--- a/src/uix/soma/components/progress/progress-provider.svelte.ts
+++ b/src/uix/soma/components/progress/progress-provider.svelte.ts
@@ -7,7 +7,6 @@ import type { Orientation } from '../../types';
 import { progressMorfo } from '../../../morfo/components/progress';
 import type { SomaRuntime, SomaRuntimePart } from '../../runtime.svelte';
 
-
 function computeState(value: number | null, min: number, max: number): ProgressState {
 	if (value === null) return 'indeterminate';
 	if (value >= max) return 'loaded';
@@ -70,8 +69,7 @@ export class ProgressProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: ProgressProvider.ctx,
-			syncAttrs: true
+			context: ProgressProvider.ctx
 		});
 	}
 
@@ -134,8 +132,7 @@ export class ProgressLabelProvider {
 		this.runtimePart = this.provider.runtime.part('label', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -165,8 +162,7 @@ export class ProgressValueTextProvider {
 		this.runtimePart = this.provider.runtime.part('value-text', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -210,8 +206,7 @@ export class ProgressIndicatorProvider {
 			states: {
 				loading: () => this.provider.state
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/rating-group/rating-group-provider.svelte.test.ts b/src/uix/soma/components/rating-group/rating-group-provider.svelte.test.ts
index c6fc8fdb1..1673fd22e 100644
--- a/src/uix/soma/components/rating-group/rating-group-provider.svelte.test.ts
+++ b/src/uix/soma/components/rating-group/rating-group-provider.svelte.test.ts
@@ -162,21 +162,28 @@ describe('RatingGroupProvider', () => {
 
 		result.provider.onfocus();
 		await tick();
-		expect(root.getAttribute('role')).toBe('slider');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.provider.props.role).toBe('slider');
 		// Naming default: ships in the render bag (consumerWins, A-85).
 		expect(result.provider.props).toMatchObject({ 'aria-label': 'Rating' });
-		expect(root.getAttribute('aria-valuenow')).toBe('2.5');
-		expect(root.getAttribute('aria-valuemin')).toBe('0');
-		expect(root.getAttribute('aria-valuemax')).toBe('5');
-		expect(root.getAttribute('aria-valuetext')).toBe('2.5 out of 5');
-		expect(root.getAttribute('data-required')).toBe('');
-		expect(root.getAttribute('data-invalid')).toBe('');
-		expect(root.getAttribute('data-focused')).toBe('');
-		expect(activeEl.getAttribute('role')).toBe('presentation');
-		expect(activeEl.getAttribute('data-state')).toBe('active');
-		expect(activeEl.getAttribute('data-value')).toBe('2');
-		expect(partialEl.getAttribute('data-state')).toBe('partial');
-		expect(partialEl.getAttribute('data-value')).toBe('3');
+		expect(result.provider.props).toMatchObject({
+			'aria-valuenow': 2.5,
+			'aria-valuemin': 0,
+			'aria-valuemax': 5,
+			'aria-valuetext': '2.5 out of 5',
+			'data-required': '',
+			'data-invalid': '',
+			'data-focused': ''
+		});
+		expect(result.active.props).toMatchObject({
+			role: 'presentation',
+			'data-state': 'active',
+			'data-value': 2
+		});
+		expect(result.partial.props).toMatchObject({
+			'data-state': 'partial',
+			'data-value': 3
+		});
 
 		cleanup();
 		dom.dispose();
@@ -199,9 +206,10 @@ describe('RatingGroupProvider', () => {
 		// through dom.apply since A-85, which would make a DOM-only check pass
 		// trivially and stop guarding anything.
 		expect(provider.props).not.toHaveProperty('aria-label');
-		expect(root.hasAttribute('aria-label')).toBe(false);
-		expect(root.getAttribute('aria-labelledby')).toBe('rating-label');
-		expect(root.getAttribute('aria-valuetext')).toBe('Two and a half stars');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect('aria-label' in provider.props).toBe(false);
+		expect(provider.props['aria-labelledby']).toBe('rating-label');
+		expect(provider.props['aria-valuetext']).toBe('Two and a half stars');
 
 		cleanup();
 		dom.dispose();
diff --git a/src/uix/soma/components/rating-group/rating-group-provider.svelte.ts b/src/uix/soma/components/rating-group/rating-group-provider.svelte.ts
index 094167309..a83a13f20 100644
--- a/src/uix/soma/components/rating-group/rating-group-provider.svelte.ts
+++ b/src/uix/soma/components/rating-group/rating-group-provider.svelte.ts
@@ -109,8 +109,7 @@ export class RatingGroupProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: RatingGroupProvider.ctx,
-			syncAttrs: true
+			context: RatingGroupProvider.ctx
 		});
 	}
 
@@ -350,8 +349,7 @@ export class RatingGroupItemProvider {
 				readonly: () => this.provider.isReadonly,
 				orientation: () => this.provider.opts.orientation.current,
 				value: () => this.opts.index.current + 1
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
diff --git a/src/uix/soma/components/search-field/search-field-provider.svelte.test.ts b/src/uix/soma/components/search-field/search-field-provider.svelte.test.ts
index 49c0e4b25..f11f3f663 100644
--- a/src/uix/soma/components/search-field/search-field-provider.svelte.test.ts
+++ b/src/uix/soma/components/search-field/search-field-provider.svelte.test.ts
@@ -136,19 +136,20 @@ describe('SearchFieldProvider', () => {
 		});
 
 		await tick();
-		expect(root.getAttribute('data-required')).toBe('');
-		expect(root.getAttribute('data-invalid')).toBe('');
-		expect(root.getAttribute('data-empty')).toBe('');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.provider.props['data-required']).toBe('');
+		expect(result.provider.props['data-invalid']).toBe('');
+		expect(result.provider.props['data-empty']).toBe('');
 
 		result.input.props.onfocus({ currentTarget: inputEl } as never);
 		await tick();
 		expect(result.provider.snippetProps.isFocused).toBe(true);
-		expect(root.getAttribute('data-focused')).toBe('');
+		expect(result.provider.props['data-focused']).toBe('');
 
 		result.input.props.onblur({ currentTarget: inputEl } as never);
 		await tick();
 		expect(result.provider.snippetProps.isFocused).toBe(false);
-		expect(root.hasAttribute('data-focused')).toBe(false);
+		expect('data-focused' in result.provider.props).toBe(false);
 
 		cleanup();
 		dom.dispose();
diff --git a/src/uix/soma/components/search-field/search-field-provider.svelte.ts b/src/uix/soma/components/search-field/search-field-provider.svelte.ts
index 70b8652c7..ab11b9431 100644
--- a/src/uix/soma/components/search-field/search-field-provider.svelte.ts
+++ b/src/uix/soma/components/search-field/search-field-provider.svelte.ts
@@ -93,8 +93,7 @@ export class SearchFieldProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: SearchFieldProvider.ctx,
-			syncAttrs: true
+			context: SearchFieldProvider.ctx
 		});
 		// Register the Input's id with the parent Field so `Field.Label`'s
 		// `for` attribute lands on the interactive element. Direct assign —
diff --git a/src/uix/soma/components/select/select-provider.svelte.ts b/src/uix/soma/components/select/select-provider.svelte.ts
index e94a4f35f..af2176b03 100644
--- a/src/uix/soma/components/select/select-provider.svelte.ts
+++ b/src/uix/soma/components/select/select-provider.svelte.ts
@@ -25,10 +25,7 @@ import { Typeahead } from '../../typeahead';
 import { Presence } from '../../layers/presence.svelte';
 import { Dismissal, type DismissalBehavior } from '../../layers/dismissal.svelte';
 import { ScrollLock } from '../../layers/scroll-lock.svelte';
-import {
-	computeListSelection,
-	resolveListItemEl
-} from '../../layers/list-selection';
+import { computeListSelection, resolveListItemEl } from '../../layers/list-selection';
 import {
 	FloatingProvider,
 	FloatingContent,
@@ -149,8 +146,7 @@ export class SelectProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: SelectProvider.ctx,
-			syncAttrs: true
+			context: SelectProvider.ctx
 		});
 
 		const shell = createFloatingShellRoot({
@@ -280,7 +276,7 @@ export class SelectProvider {
 
 	readonly props = $derived.by(() =>
 		this.runtimePart.assert({
-			...this.runtimePart.props,
+			...this.runtimePart.props
 			// Raw, so no assertion leaves the root inheriting. The in-place half paints
 			// from it: the trigger's flex row (the indicator swaps sides) and
 			// `[data-select-value] { text-align: start }`. The portalled half is the
@@ -430,7 +426,6 @@ export class SelectTriggerProvider {
 interface SelectValueOpts extends WithRefOpts, ActiveProps<{ placeholder: string }> {}
 
 export class SelectValueProvider {
-
 	readonly opts: SelectValueOpts;
 	readonly runtimePart: SomaRuntimePart<typeof selectMorfo, 'value'>;
 	static create(opts: SelectValueOpts) {
diff --git a/src/uix/soma/components/slider/slider-provider.svelte.test.ts b/src/uix/soma/components/slider/slider-provider.svelte.test.ts
index b5b43e653..8347dd6de 100644
--- a/src/uix/soma/components/slider/slider-provider.svelte.test.ts
+++ b/src/uix/soma/components/slider/slider-provider.svelte.test.ts
@@ -254,15 +254,16 @@ describe('SliderProvider', () => {
 		});
 
 		await tick();
-		expect(root.getAttribute('role')).toBe('group');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.provider.props.role).toBe('group');
 		// The group declares no `aria-label`: a NAMING attr with no framework
 		// default (A-85), so the bag stays clean and the consumer's own attr
 		// rides restProps to the element. The Thumb keeps one — it is fed by
 		// `thumbLabels`, asserted above.
 		expect(result.provider.props).not.toHaveProperty('aria-label');
-		expect(root.getAttribute('data-orientation')).toBe('horizontal');
-		expect(tickEl.getAttribute('data-value')).toBe('50');
-		expect(tickEl.getAttribute('data-active')).toBe('');
+		expect(result.provider.props['data-orientation']).toBe('horizontal');
+		expect(result.tick.props['data-value']).toBe(50);
+		expect(result.tick.props['data-active']).toBe('');
 
 		cleanup();
 		dom.dispose();
@@ -350,8 +351,9 @@ describe('SliderProvider', () => {
 		// Nothing names the group from the framework side (A-85): no bag entry,
 		// hence no attribute either — only the reference the consumer gave.
 		expect(provider.props).not.toHaveProperty('aria-label');
-		expect(root.hasAttribute('aria-label')).toBe(false);
-		expect(root.getAttribute('aria-labelledby')).toBe('external-label');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect('aria-label' in provider.props).toBe(false);
+		expect(provider.props['aria-labelledby']).toBe('external-label');
 
 		cleanup();
 		dom.dispose();
@@ -371,8 +373,9 @@ describe('SliderProvider', () => {
 
 		await tick();
 		expect(provider.isDisabled).toBe(true);
-		expect(root.getAttribute('data-disabled')).toBe('');
-		expect(root.getAttribute('aria-labelledby')).toBe('field-label');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(provider.props['data-disabled']).toBe('');
+		expect(provider.props['aria-labelledby']).toBe('field-label');
 
 		cleanup();
 		dom.dispose();
diff --git a/src/uix/soma/components/slider/slider-provider.svelte.ts b/src/uix/soma/components/slider/slider-provider.svelte.ts
index e3be2e0f9..89b8c2537 100644
--- a/src/uix/soma/components/slider/slider-provider.svelte.ts
+++ b/src/uix/soma/components/slider/slider-provider.svelte.ts
@@ -129,8 +129,7 @@ export class SliderProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: SliderProvider.ctx,
-			syncAttrs: true
+			context: SliderProvider.ctx
 		});
 	}
 
@@ -424,8 +423,7 @@ export class SliderRangeProvider {
 		this.runtimePart = this.provider.runtime.part('range', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -483,8 +481,7 @@ export class SliderSecondaryRangeProvider {
 		this.runtimePart = this.provider.runtime.part('secondary-range', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -664,8 +661,7 @@ export class SliderTickProvider {
 				value: () => this.opts.value.current,
 				orientation: () => this.provider.opts.orientation.current,
 				active: () => this.isActive
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
diff --git a/src/uix/soma/components/splitter/splitter-provider.svelte.test.ts b/src/uix/soma/components/splitter/splitter-provider.svelte.test.ts
index d6917a2ac..8888508a0 100644
--- a/src/uix/soma/components/splitter/splitter-provider.svelte.test.ts
+++ b/src/uix/soma/components/splitter/splitter-provider.svelte.test.ts
@@ -145,12 +145,17 @@ describe('SplitterProvider', () => {
 		expect(result.provider.getSizes()).toEqual([90, 10]);
 
 		await tick();
-		expect(root.getAttribute('data-orientation')).toBe('horizontal');
-		expect(root.getAttribute('data-disabled')).toBe('');
-		expect(panelAEl.getAttribute('data-state')).toBe('expanded');
-		expect(panelAEl.getAttribute('data-orientation')).toBe('horizontal');
-		expect(panelAEl.getAttribute('data-splitter-panel-id')).toBe('a');
-		expect(panelBEl.getAttribute('data-splitter-panel-id')).toBe('b');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.provider.props).toMatchObject({
+			'data-orientation': 'horizontal',
+			'data-disabled': ''
+		});
+		expect(result.panelA.props).toMatchObject({
+			'data-state': 'expanded',
+			'data-orientation': 'horizontal',
+			'data-splitter-panel-id': 'a'
+		});
+		expect(result.panelB.props['data-splitter-panel-id']).toBe('b');
 
 		cleanup();
 		dom.dispose();
@@ -290,14 +295,16 @@ describe('SplitterProvider', () => {
 		expect(result.provider.getSizes()).toEqual([90, 10]);
 
 		await tick();
-		expect(root.getAttribute('data-resizing')).toBeNull();
-		expect(triggerEl.getAttribute('role')).toBe('separator');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect('data-resizing' in result.provider.props).toBe(false);
+		expect(result.trigger.props['role']).toBe('separator');
 		// Naming default: ships in the render bag (consumerWins, A-85).
 		expect(result.trigger.props).toMatchObject({ 'aria-label': 'Resize panels' });
-		expect(triggerEl.getAttribute('aria-valuenow')).toBe('90');
-		expect(triggerEl.getAttribute('aria-valuemin')).toBe('10');
-		expect(triggerEl.getAttribute('aria-valuemax')).toBe('90');
-		expect(triggerEl.getAttribute('data-state')).toBe('inactive');
+		// The bag carries the raw numbers; the DOM stringified them.
+		expect(result.trigger.props['aria-valuenow']).toBe(90);
+		expect(result.trigger.props['aria-valuemin']).toBe(10);
+		expect(result.trigger.props['aria-valuemax']).toBe(90);
+		expect(result.trigger.props['data-state']).toBe('inactive');
 
 		cleanup();
 		dom.dispose();
diff --git a/src/uix/soma/components/splitter/splitter-provider.svelte.ts b/src/uix/soma/components/splitter/splitter-provider.svelte.ts
index 501523a6a..5b53e33bd 100644
--- a/src/uix/soma/components/splitter/splitter-provider.svelte.ts
+++ b/src/uix/soma/components/splitter/splitter-provider.svelte.ts
@@ -18,7 +18,6 @@ function clamp(value: number, min: number, max: number): number {
 	return value < min ? min : value > max ? max : value;
 }
 
-
 // ── Types ────────────────────────────────────────────────────────────────────
 
 export interface PanelConfig {
@@ -115,8 +114,7 @@ export class SplitterProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: SplitterProvider.ctx,
-			syncAttrs: true
+			context: SplitterProvider.ctx
 		});
 
 		// Controlled layout (bindable pair `sizes` + `onSizesChange`): an
@@ -358,8 +356,7 @@ export class SplitterPanelProvider {
 				state: () => (this.isCollapsed ? 'collapsed' : 'expanded'),
 				orientation: () => this.provider.opts.orientation.current,
 				panelId: () => this.opts.panelId.current
-			},
-			syncAttrs: true
+			}
 		});
 
 		this.cleanup = this.provider.registerPanel({
@@ -518,8 +515,7 @@ export class SplitterResizeTriggerProvider {
 				size: () => this.ariaValueNow,
 				minSize: () => this.ariaValueMin,
 				maxSize: () => this.ariaValueMax
-			},
-			syncAttrs: true
+			}
 		});
 
 		// Cleanup drag state on unmount
diff --git a/src/uix/soma/components/stepper/stepper-provider.svelte.test.ts b/src/uix/soma/components/stepper/stepper-provider.svelte.test.ts
index 7ba97dd56..7fe0bbc4c 100644
--- a/src/uix/soma/components/stepper/stepper-provider.svelte.test.ts
+++ b/src/uix/soma/components/stepper/stepper-provider.svelte.test.ts
@@ -148,17 +148,26 @@ describe('StepperProvider', () => {
 		expect(result.current.contentId.current).toBe('stepper-content-1');
 
 		await tick();
-		expect(root.getAttribute('data-orientation')).toBe('horizontal');
-		expect(root.getAttribute('data-linear')).toBe('');
-		expect(firstEl.getAttribute('data-state')).toBe('complete');
-		expect(currentEl.getAttribute('data-state')).toBe('current');
-		expect(lastEl.getAttribute('data-state')).toBe('incomplete');
-		expect(indicatorEl.getAttribute('aria-hidden')).toBe('true');
-		expect(indicatorEl.getAttribute('data-state')).toBe('current');
-		expect(separatorEl.getAttribute('role')).toBe('separator');
-		expect(separatorEl.getAttribute('data-orientation')).toBe('horizontal');
-		expect(contentEl.getAttribute('role')).toBe('tabpanel');
-		expect(contentEl.getAttribute('data-state')).toBe('current');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.provider.props).toMatchObject({
+			'data-orientation': 'horizontal',
+			'data-linear': ''
+		});
+		expect(result.first.props['data-state']).toBe('complete');
+		expect(result.current.props['data-state']).toBe('current');
+		expect(result.last.props['data-state']).toBe('incomplete');
+		expect(result.indicator.props).toMatchObject({
+			'aria-hidden': 'true',
+			'data-state': 'current'
+		});
+		expect(result.separator.props).toMatchObject({
+			role: 'separator',
+			'data-orientation': 'horizontal'
+		});
+		expect(result.content.props).toMatchObject({
+			role: 'tabpanel',
+			'data-state': 'current'
+		});
 
 		cleanup();
 		dom.dispose();
@@ -308,7 +317,8 @@ describe('StepperProvider', () => {
 		// 'complete' is the morfo's enum member — this assertion used to pin the
 		// drifted 'completed' the provider emitted, i.e. it was written against
 		// the implementation, not the contract (P0 fase A, audit 2026-08-26).
-		expect(completedEl.getAttribute('data-state')).toBe('complete');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.completed.props['data-state']).toBe('complete');
 
 		cleanup();
 		dom.dispose();
diff --git a/src/uix/soma/components/stepper/stepper-provider.svelte.ts b/src/uix/soma/components/stepper/stepper-provider.svelte.ts
index 7a88e57b8..7663fc0d3 100644
--- a/src/uix/soma/components/stepper/stepper-provider.svelte.ts
+++ b/src/uix/soma/components/stepper/stepper-provider.svelte.ts
@@ -94,8 +94,7 @@ export class StepperProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: StepperProvider.ctx,
-			syncAttrs: true
+			context: StepperProvider.ctx
 		});
 	}
 
@@ -228,8 +227,7 @@ export class StepperItemProvider {
 			props: {
 				state: () => this.stepState,
 				orientation: () => this.provider.opts.orientation.current
-			},
-			syncAttrs: true
+			}
 		});
 
 		// Track count: increment on mount, decrement on unmount
@@ -381,8 +379,7 @@ export class StepperIndicatorProvider {
 			owner: this,
 			props: {
 				state: () => this.item.stepState
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
@@ -421,8 +418,7 @@ export class StepperSeparatorProvider {
 			props: {
 				state: () => this.item.stepState,
 				orientation: () => this.provider.opts.orientation.current
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
@@ -460,8 +456,7 @@ export class StepperContentProvider {
 			owner: this,
 			props: {
 				state: () => this.stepState
-			},
-			syncAttrs: true
+			}
 		});
 		// Content can be inside or outside an Item — use get() not require()
 		const item = StepperItemProvider.get();
@@ -506,8 +501,7 @@ export class StepperCompletedContentProvider {
 				// outside `values: ['complete', 'current', 'incomplete']` — caught
 				// by perm-check the first time it ran.
 				state: () => 'complete'
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
diff --git a/src/uix/soma/components/sticky/sticky-provider.svelte.test.ts b/src/uix/soma/components/sticky/sticky-provider.svelte.test.ts
index 9384aa9f1..8b9c9e114 100644
--- a/src/uix/soma/components/sticky/sticky-provider.svelte.test.ts
+++ b/src/uix/soma/components/sticky/sticky-provider.svelte.test.ts
@@ -64,7 +64,7 @@ afterEach(() => {
 });
 
 describe('StickyProvider', () => {
-	it('stamps data-edge + aria-hidden via syncAttrs, exposes the marker and offset on the props bag, and starts unstuck', async () => {
+	it('stamps data-edge + aria-hidden via the render bag, exposes the marker and offset on the props bag, and starts unstuck', async () => {
 		installSomaHarness();
 		const box = document.createElement('div');
 		const sentinel = document.createElement('div');
@@ -73,23 +73,21 @@ describe('StickyProvider', () => {
 		const { result, cleanup } = withEffectRoot(() =>
 			StickyProvider.create(stickyOpts(box, sentinel, { offset: 64, edge: 'top' }))
 		);
-		// touch the reactive prop bags so the syncAttrs effects run
-		void result.boxProps;
-		void result.sentinelProps;
 		await tick();
 
-		// syncAttrs writes the morfo attrs directly to the refs:
-		expect(box.getAttribute('data-edge')).toBe('top');
-		expect(box.hasAttribute('data-stuck')).toBe(false); // unstuck by default
-		expect(sentinel.getAttribute('data-edge')).toBe('top');
-		expect(sentinel.getAttribute('aria-hidden')).toBe('true');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		const boxProps = result.boxProps as Record<string, unknown>;
+		const sentinelProps = result.sentinelProps as Record<string, unknown>;
+		expect(boxProps['data-edge']).toBe('top');
+		expect('data-stuck' in boxProps).toBe(false); // unstuck by default
+		expect(sentinelProps['data-edge']).toBe('top');
+		expect(sentinelProps['aria-hidden']).toBe('true');
 
 		// The bare part marker + offset data ride the props bag (the wrapper
 		// spreads them; a headless unit test doesn't render):
-		const boxProps = result.boxProps as Record<string, unknown>;
 		expect(boxProps['data-sticky']).toBe('');
 		expect((boxProps.style as Record<string, string>)['--_sticky-offset']).toBe('64px');
-		expect((result.sentinelProps as Record<string, unknown>)['data-sticky-sentinel']).toBe('');
+		expect(sentinelProps['data-sticky-sentinel']).toBe('');
 
 		cleanup();
 	});
@@ -112,7 +110,6 @@ describe('StickyProvider', () => {
 		const { result, cleanup } = withEffectRoot(() =>
 			StickyProvider.create(stickyOpts(box, sentinel, { offset: 80, edge: 'top' }))
 		);
-		void result.boxProps;
 		await tick();
 
 		expect(observeIntersection).toHaveBeenCalledWith(
@@ -128,7 +125,8 @@ describe('StickyProvider', () => {
 		);
 		await tick();
 		expect(result.stuck).toBe(true);
-		expect(box.getAttribute('data-stuck')).toBe('');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect((result.boxProps as Record<string, unknown>)['data-stuck']).toBe('');
 
 		// Sentinel back in view → unstuck, attr removed.
 		observerCallback(
@@ -137,7 +135,7 @@ describe('StickyProvider', () => {
 		);
 		await tick();
 		expect(result.stuck).toBe(false);
-		expect(box.hasAttribute('data-stuck')).toBe(false);
+		expect('data-stuck' in result.boxProps).toBe(false);
 
 		cleanup();
 		expect(observerCleanup).toHaveBeenCalledOnce();
@@ -153,12 +151,11 @@ describe('StickyProvider', () => {
 		const { result, cleanup } = withEffectRoot(() =>
 			StickyProvider.create(stickyOpts(box, sentinel, { offset: 24, edge: 'bottom' }))
 		);
-		void result.boxProps;
-		void result.sentinelProps;
 		await tick();
 
-		expect(box.getAttribute('data-edge')).toBe('bottom');
-		expect(sentinel.getAttribute('data-edge')).toBe('bottom');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect((result.boxProps as Record<string, unknown>)['data-edge']).toBe('bottom');
+		expect((result.sentinelProps as Record<string, unknown>)['data-edge']).toBe('bottom');
 		expect(observeIntersection).toHaveBeenCalledWith(
 			sentinel,
 			expect.any(Function),
@@ -178,7 +175,6 @@ describe('StickyProvider', () => {
 		const { result, cleanup } = withEffectRoot(() =>
 			StickyProvider.create(stickyOpts(box, sentinel, { disabled: true }))
 		);
-		void result.boxProps;
 		await tick();
 
 		expect(observeIntersection).not.toHaveBeenCalled();
diff --git a/src/uix/soma/components/sticky/sticky-provider.svelte.ts b/src/uix/soma/components/sticky/sticky-provider.svelte.ts
index 28fb9bb84..f841b9ed0 100644
--- a/src/uix/soma/components/sticky/sticky-provider.svelte.ts
+++ b/src/uix/soma/components/sticky/sticky-provider.svelte.ts
@@ -44,8 +44,8 @@ interface StickyOpts
  * The observation lives in one `$effect` on the sentinel ref that RETURNS
  * `soma.dom.observeIntersection(...)` as its teardown (mirrors
  * FeedSentinelProvider). The async callback flips `stuck = $state`; the
- * runtime's `syncAttrs` effect is the single writer that materializes
- * `data-stuck` / `data-edge` from the part's `props` sources. The provider
+ * render bag materializes `data-stuck` / `data-edge` from the part's
+ * `props` sources. The provider
  * emits NO visual CSS — only the offset as a custom-property `style`
  * (A8-allowed data, meter precedent); `position: sticky` lives in the eidos
  * recipe.
@@ -84,14 +84,12 @@ export class StickyProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: StickyProvider.ctx,
-			syncAttrs: true
+			context: StickyProvider.ctx
 		});
 		this.sentinelPart = this.runtime.part('sentinel', {
 			id: opts.sentinelId,
 			ref: opts.sentinelRef,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 
 		$effect(() => {
diff --git a/src/uix/soma/components/switch/switch-provider.svelte.ts b/src/uix/soma/components/switch/switch-provider.svelte.ts
index 403b7e32a..369925839 100644
--- a/src/uix/soma/components/switch/switch-provider.svelte.ts
+++ b/src/uix/soma/components/switch/switch-provider.svelte.ts
@@ -126,8 +126,7 @@ export class SwitchProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: SwitchProvider.ctx,
-			syncAttrs: true
+			context: SwitchProvider.ctx
 		});
 	}
 
@@ -213,8 +212,7 @@ export class SwitchThumbProvider {
 		this.runtimePart = this.provider.runtime.part('thumb', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/tag-group/tag-group-provider.svelte.test.ts b/src/uix/soma/components/tag-group/tag-group-provider.svelte.test.ts
index 00a6b1db5..88a469f1b 100644
--- a/src/uix/soma/components/tag-group/tag-group-provider.svelte.test.ts
+++ b/src/uix/soma/components/tag-group/tag-group-provider.svelte.test.ts
@@ -188,10 +188,13 @@ describe('TagGroupProvider', () => {
 		expect(onValueChange).toHaveBeenLastCalledWith([]);
 
 		await tick();
-		expect(root.getAttribute('role')).toBe('grid');
-		expect(root.getAttribute('aria-labelledby')).toBe('tag-group-label');
-		expect(root.getAttribute('aria-multiselectable')).toBe('true');
-		expect(root.getAttribute('data-selection-mode')).toBe('multiple');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.provider.props).toMatchObject({
+			role: 'grid',
+			'aria-labelledby': 'tag-group-label',
+			'aria-multiselectable': 'true',
+			'data-selection-mode': 'multiple'
+		});
 
 		cleanup();
 		dom.dispose();
diff --git a/src/uix/soma/components/tag-group/tag-group-provider.svelte.ts b/src/uix/soma/components/tag-group/tag-group-provider.svelte.ts
index fa4951736..fb0f1ad6b 100644
--- a/src/uix/soma/components/tag-group/tag-group-provider.svelte.ts
+++ b/src/uix/soma/components/tag-group/tag-group-provider.svelte.ts
@@ -72,8 +72,7 @@ export class TagGroupProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: TagGroupProvider.ctx,
-			syncAttrs: true
+			context: TagGroupProvider.ctx
 		});
 	}
 
@@ -83,7 +82,9 @@ export class TagGroupProvider {
 	 * The chain `prop → soma.prefs.getDir() → 'ltr'` runs in the WRAPPER
 	 * (`activeDir`), so this only supplies the final fallback.
 	 */
-	readonly resolvedDir: Active<Direction> = readableActive(() => resolveDir(this.opts.dir, this.soma));
+	readonly resolvedDir: Active<Direction> = readableActive(() =>
+		resolveDir(this.opts.dir, this.soma)
+	);
 
 	readonly resolvedAriaLabelledby = $derived.by(
 		() => this.opts.ariaLabelledby.current || this.labelId.current || undefined
@@ -246,7 +247,7 @@ export class TagGroupProvider {
 
 	readonly props = $derived.by(() =>
 		this.runtimePart.assert({
-			...this.runtimePart.props,
+			...this.runtimePart.props
 			// The RAW assertion, never the resolved value: omitted when nobody
 			// asserted a direction, so the element inherits instead of forcing
 			// `ltr`. `resolvedDir` is the other half, for the maths.
diff --git a/src/uix/soma/components/tags-input/tags-input-provider.svelte.test.ts b/src/uix/soma/components/tags-input/tags-input-provider.svelte.test.ts
index b7f09dbc6..4c5aec689 100644
--- a/src/uix/soma/components/tags-input/tags-input-provider.svelte.test.ts
+++ b/src/uix/soma/components/tags-input/tags-input-provider.svelte.test.ts
@@ -170,12 +170,13 @@ describe('TagsInputProvider', () => {
 		// FIRMA 2026-08-25 — the provider carries no role (it owned no option of
 		// its own) and the control IS the layout grid the `apg` cites.
 		// `aria-orientation` went with the listbox: `grid` does not support it.
-		expect(root.hasAttribute('role')).toBe(false);
-		expect(root.hasAttribute('aria-orientation')).toBe(false);
-		expect(root.hasAttribute('data-empty')).toBe(false);
-		expect(controlEl.getAttribute('role')).toBe('grid');
-		expect(controlEl.hasAttribute('aria-orientation')).toBe(false);
-		expect(controlEl.getAttribute('data-focus')).toBe('');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect('role' in result.provider.props).toBe(false);
+		expect('aria-orientation' in result.provider.props).toBe(false);
+		expect('data-empty' in result.provider.props).toBe(false);
+		expect(result.control.props['role']).toBe('grid');
+		expect('aria-orientation' in result.control.props).toBe(false);
+		expect(result.control.props['data-focus']).toBe('');
 
 		cleanup();
 		dom.dispose();
diff --git a/src/uix/soma/components/tags-input/tags-input-provider.svelte.ts b/src/uix/soma/components/tags-input/tags-input-provider.svelte.ts
index b40847ee8..f92a8b682 100644
--- a/src/uix/soma/components/tags-input/tags-input-provider.svelte.ts
+++ b/src/uix/soma/components/tags-input/tags-input-provider.svelte.ts
@@ -74,8 +74,7 @@ export class TagsInputProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: TagsInputProvider.ctx,
-			syncAttrs: true
+			context: TagsInputProvider.ctx
 		});
 	}
 
@@ -315,8 +314,7 @@ export class TagsInputControlProvider {
 		this.runtimePart = this.provider.runtime.part('control', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/textarea/textarea-provider.svelte.ts b/src/uix/soma/components/textarea/textarea-provider.svelte.ts
index 6159bb8b6..ab7690622 100644
--- a/src/uix/soma/components/textarea/textarea-provider.svelte.ts
+++ b/src/uix/soma/components/textarea/textarea-provider.svelte.ts
@@ -1,11 +1,6 @@
 import { context, type WithRefOpts } from '../../provider';
 import { state, type ActiveProps, type StateProps } from '$libs/reactive';
-import type {
-	OnChangeFn,
-	SomaFocusEvent,
-	SomaInputEvent,
-	SomaKeyboardEvent
-} from '../../types';
+import type { OnChangeFn, SomaFocusEvent, SomaInputEvent, SomaKeyboardEvent } from '../../types';
 import { KEYS } from '../../keyboard';
 import { Soma } from '../../core/soma.svelte';
 import { FieldProvider } from '../field';
@@ -93,8 +88,7 @@ export class TextAreaProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: TextAreaProvider.ctx,
-			syncAttrs: true
+			context: TextAreaProvider.ctx
 		});
 
 		// Register Input id with parent Field so `Field.Label`'s `for=` lands.
@@ -134,7 +128,6 @@ export class TextAreaProvider {
 		return this.opts.resize.current ?? 'vertical';
 	});
 
-
 	setInputRef(el: HTMLTextAreaElement | null) {
 		this.inputRef.current = el;
 	}
@@ -299,10 +292,9 @@ export class TextAreaInputProvider {
 	readonly describedBy = $derived.by(() => {
 		const field = this.provider.field;
 		if (!field) return undefined;
-		const ids = [
-			field.helperId.current,
-			field.isInvalid ? field.errorId.current : ''
-		].filter(Boolean);
+		const ids = [field.helperId.current, field.isInvalid ? field.errorId.current : ''].filter(
+			Boolean
+		);
 		return ids.length > 0 ? ids.join(' ') : undefined;
 	});
 
diff --git a/src/uix/soma/components/time-field/time-field-provider.svelte.ts b/src/uix/soma/components/time-field/time-field-provider.svelte.ts
index eaa169265..bc69271ec 100644
--- a/src/uix/soma/components/time-field/time-field-provider.svelte.ts
+++ b/src/uix/soma/components/time-field/time-field-provider.svelte.ts
@@ -182,8 +182,7 @@ export class TimeFieldProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: TimeFieldProvider.ctx,
-			syncAttrs: true
+			context: TimeFieldProvider.ctx
 		});
 
 		this.segmentValues = initializeTimeSegmentValues();
@@ -608,8 +607,7 @@ export class TimeFieldLabelProvider {
 			owner: this,
 			onRefChange: (v) => {
 				this.provider.labelNode = v;
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
diff --git a/src/uix/soma/components/time-range-field/time-range-field-provider.svelte.ts b/src/uix/soma/components/time-range-field/time-range-field-provider.svelte.ts
index b9ad36f5f..d6ce58aaf 100644
--- a/src/uix/soma/components/time-range-field/time-range-field-provider.svelte.ts
+++ b/src/uix/soma/components/time-range-field/time-range-field-provider.svelte.ts
@@ -106,8 +106,7 @@ export class TimeRangeFieldProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: TimeRangeFieldProvider.ctx,
-			syncAttrs: true
+			context: TimeRangeFieldProvider.ctx
 		});
 	}
 
@@ -202,8 +201,7 @@ export class TimeRangeFieldLabelProvider {
 			owner: this,
 			onRefChange: (v) => {
 				this.provider.labelNode = v;
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
diff --git a/src/uix/soma/components/toast/toast-provider.svelte.test.ts b/src/uix/soma/components/toast/toast-provider.svelte.test.ts
index 0ba2cb52b..fddf17499 100644
--- a/src/uix/soma/components/toast/toast-provider.svelte.test.ts
+++ b/src/uix/soma/components/toast/toast-provider.svelte.test.ts
@@ -126,10 +126,11 @@ describe('ToastProvider parts', () => {
 			tabindex: -1
 		});
 		await tick();
-		expect(viewportEl.getAttribute('role')).toBe('region');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.viewport.props['role']).toBe('region');
 		// Naming default: ships in the render bag (consumerWins, A-85).
 		expect(result.viewport.props).toMatchObject({ 'aria-label': 'Notifications' });
-		expect(viewportEl.getAttribute('aria-live')).toBe('polite');
+		expect(result.viewport.props['aria-live']).toBe('polite');
 
 		document.dispatchEvent(keyboardEvent('Alt', 'AltLeft', { altKey: true }));
 		const f8 = keyboardEvent('F8', 'F8', { altKey: true });
@@ -218,21 +219,24 @@ describe('ToastProvider parts', () => {
 		expect(result.close.props.onclick).toBe(result.close.onclick);
 
 		await tick();
-		expect(itemEl.getAttribute('role')).toBe('alert');
-		expect(itemEl.getAttribute('aria-live')).toBe('assertive');
-		expect(itemEl.getAttribute('aria-atomic')).toBe('true');
-		expect(itemEl.getAttribute('aria-labelledby')).toBe('toast-title');
-		expect(itemEl.getAttribute('aria-describedby')).toBe('toast-description');
-		expect(itemEl.getAttribute('data-intent')).toBe('risk');
-		expect(itemEl.getAttribute('data-loading')).toBe('');
-		expect(itemEl.hasAttribute('data-swipe')).toBe(false);
-		expect(itemEl.getAttribute('data-swipe-direction')).toBe('right');
-		expect(actionEl.getAttribute('type')).toBe('button');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.item.props).toMatchObject({
+			role: 'alert',
+			'aria-live': 'assertive',
+			'aria-atomic': 'true',
+			'aria-labelledby': 'toast-title',
+			'aria-describedby': 'toast-description',
+			'data-intent': 'risk',
+			'data-loading': '',
+			'data-swipe-direction': 'right'
+		});
+		expect('data-swipe' in result.item.props).toBe(false);
+		expect(result.action.props['type']).toBe('button');
 		// Naming default: ships in the render bag (consumerWins, A-85).
 		expect(result.action.props).toMatchObject({ 'aria-label': 'Undo save' });
-		expect(closeEl.getAttribute('type')).toBe('button');
+		expect(result.close.props['type']).toBe('button');
 		expect(result.close.props).toMatchObject({ 'aria-label': 'Close' });
-		expect(statusEl.getAttribute('aria-hidden')).toBe('true');
+		expect(result.status.props['aria-hidden']).toBe('true');
 
 		result.item.onpointerenter();
 		expect(harness.handles.get('soma:toast:auto-dismiss:toast-item')?.cancel).toHaveBeenCalled();
@@ -244,7 +248,7 @@ describe('ToastProvider parts', () => {
 		expect(toaster.toasts.find((toast) => toast.id === id)?.dismissing).toBe(true);
 		toastState.current = toaster.toasts[0]!;
 		await tick();
-		expect(itemEl.getAttribute('data-state')).toBe('closed');
+		expect(result.item.props['data-state']).toBe('closed');
 
 		cleanup();
 		harness.dom.dispose();
diff --git a/src/uix/soma/components/toast/toast-provider.svelte.ts b/src/uix/soma/components/toast/toast-provider.svelte.ts
index 795a031d1..4b9e820a6 100644
--- a/src/uix/soma/components/toast/toast-provider.svelte.ts
+++ b/src/uix/soma/components/toast/toast-provider.svelte.ts
@@ -89,8 +89,7 @@ export class ToastViewportProvider {
 		this.runtimePart = this.provider.runtime.part('viewport', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 
 		// Register global hotkey to focus viewport, with cleanup. Supports
@@ -271,8 +270,7 @@ export class ToastItemProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: ToastItemProvider.ctx,
-			syncAttrs: true
+			context: ToastItemProvider.ctx
 		});
 
 		// Fire `emerge-present` (transitional, no intent) and `signal-announce`
@@ -533,8 +531,7 @@ export class ToastTitleProvider {
 		this.runtimePart = this.toastItem.runtime.part('title', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -563,8 +560,7 @@ export class ToastDescriptionProvider {
 		this.runtimePart = this.toastItem.runtime.part('description', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -603,8 +599,7 @@ export class ToastActionProvider {
 			props: {
 				altText: () => opts.altText.current
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -632,8 +627,7 @@ export class ToastCloseProvider {
 		this.runtimePart = this.toastItem.runtime.part('close', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -679,8 +673,7 @@ export class ToastStatusProvider {
 		this.runtimePart = this.toastItem.runtime.part('status', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -714,8 +707,7 @@ export class ToastMainProvider {
 		this.runtimePart = this.toastItem.runtime.part('main', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/toggle-group/toggle-group-provider.svelte.ts b/src/uix/soma/components/toggle-group/toggle-group-provider.svelte.ts
index 5c549f2d3..36f155eaa 100644
--- a/src/uix/soma/components/toggle-group/toggle-group-provider.svelte.ts
+++ b/src/uix/soma/components/toggle-group/toggle-group-provider.svelte.ts
@@ -84,8 +84,7 @@ export class ToggleGroupProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: ToggleGroupProvider.ctx,
-			syncAttrs: true
+			context: ToggleGroupProvider.ctx
 		});
 	}
 
@@ -208,8 +207,7 @@ export class ToggleGroupItemProvider {
 				orientation: () => this.provider.opts.orientation.current,
 				readonly: () => this.provider.isReadonly
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/toggle/toggle-provider.svelte.test.ts b/src/uix/soma/components/toggle/toggle-provider.svelte.test.ts
index ff026b70b..0dca42b42 100644
--- a/src/uix/soma/components/toggle/toggle-provider.svelte.test.ts
+++ b/src/uix/soma/components/toggle/toggle-provider.svelte.test.ts
@@ -107,7 +107,7 @@ describe('ToggleProvider', () => {
 		dom.dispose();
 	});
 
-	it('syncs morfo attrs through ActiveDom', async () => {
+	it('resolves morfo attrs into the render bag', async () => {
 		const { dom } = installSomaHarness();
 		const el = document.createElement('button');
 		const opts = toggleOpts();
@@ -117,18 +117,23 @@ describe('ToggleProvider', () => {
 		const { result: provider, cleanup } = withEffectRoot(() => ToggleProvider.create(opts));
 		await tick();
 
-		expect(el.getAttribute('data-state')).toBe('off');
-		expect(el.getAttribute('data-color')).toBe('primary');
-		expect(el.getAttribute('aria-pressed')).toBe('false');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(provider.props).toMatchObject({
+			'data-state': 'off',
+			'data-color': 'primary',
+			'aria-pressed': 'false'
+		});
 		// Naming default: ships in the render bag (consumerWins, A-85).
 		expect(provider.props).toMatchObject({ 'aria-label': 'Pin' });
 
 		opts.intent.current = 'threat';
 		opts.pressed.current = true;
 		await tick();
-		expect(el.getAttribute('data-state')).toBe('on');
-		expect(el.getAttribute('data-color')).toBe('threat');
-		expect(el.getAttribute('aria-pressed')).toBe('true');
+		expect(provider.props).toMatchObject({
+			'data-state': 'on',
+			'data-color': 'threat',
+			'aria-pressed': 'true'
+		});
 
 		cleanup();
 		dom.dispose();
diff --git a/src/uix/soma/components/toggle/toggle-provider.svelte.ts b/src/uix/soma/components/toggle/toggle-provider.svelte.ts
index 0958a1285..4830b5a7d 100644
--- a/src/uix/soma/components/toggle/toggle-provider.svelte.ts
+++ b/src/uix/soma/components/toggle/toggle-provider.svelte.ts
@@ -123,8 +123,7 @@ export class ToggleProvider {
 		this.runtimePart = this.runtime.part('provider', {
 			id: opts.id,
 			ref: opts.ref,
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/toolbar/toolbar-provider.svelte.test.ts b/src/uix/soma/components/toolbar/toolbar-provider.svelte.test.ts
index 46631cc9d..77611182f 100644
--- a/src/uix/soma/components/toolbar/toolbar-provider.svelte.test.ts
+++ b/src/uix/soma/components/toolbar/toolbar-provider.svelte.test.ts
@@ -129,9 +129,12 @@ describe('ToolbarProvider', () => {
 		expect(focusSpy).toHaveBeenLastCalledWith(firstEl);
 
 		await tick();
-		expect(root.getAttribute('role')).toBe('toolbar');
-		expect(root.getAttribute('data-orientation')).toBe('horizontal');
-		expect(disabledEl.getAttribute('data-disabled')).toBe('');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.provider.props).toMatchObject({
+			role: 'toolbar',
+			'data-orientation': 'horizontal'
+		});
+		expect(result.disabled.props['data-disabled']).toBe('');
 
 		cleanup();
 		dom.dispose();
@@ -212,10 +215,13 @@ describe('ToolbarProvider', () => {
 		expect(value.current).toEqual(['bold']);
 
 		await tick();
-		expect(boldEl.getAttribute('data-state')).toBe('on');
-		expect(italicEl.getAttribute('data-state')).toBe('off');
-		expect(separatorEl.getAttribute('role')).toBe('separator');
-		expect(separatorEl.getAttribute('aria-orientation')).toBe('vertical');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.bold.props['data-state']).toBe('on');
+		expect(result.italic.props['data-state']).toBe('off');
+		expect(result.separator.props).toMatchObject({
+			role: 'separator',
+			'aria-orientation': 'vertical'
+		});
 
 		groupDisabled.current = true;
 		result.bold.onclick();
diff --git a/src/uix/soma/components/toolbar/toolbar-provider.svelte.ts b/src/uix/soma/components/toolbar/toolbar-provider.svelte.ts
index 6cd8ebe99..098fbeebe 100644
--- a/src/uix/soma/components/toolbar/toolbar-provider.svelte.ts
+++ b/src/uix/soma/components/toolbar/toolbar-provider.svelte.ts
@@ -67,8 +67,7 @@ export class ToolbarProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: ToolbarProvider.ctx,
-			syncAttrs: true
+			context: ToolbarProvider.ctx
 		});
 	}
 
@@ -179,8 +178,7 @@ export class ToolbarButtonProvider {
 				disabled: () => this.opts.disabled.current,
 				orientation: () => this.provider.opts.orientation.current
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -215,8 +213,7 @@ export class ToolbarLinkProvider {
 			props: {
 				orientation: () => this.provider.opts.orientation.current
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -267,8 +264,7 @@ export class ToolbarGroupProvider {
 				orientation: () => this.provider.opts.orientation.current
 			},
 			owner: this,
-			context: ToolbarGroupProvider.ctx,
-			syncAttrs: true
+			context: ToolbarGroupProvider.ctx
 		});
 	}
 
@@ -337,8 +333,7 @@ export class ToolbarGroupItemProvider {
 				value: () => this.opts.value.current,
 				orientation: () => this.provider.opts.orientation.current
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
@@ -388,8 +383,7 @@ export class ToolbarSeparatorProvider {
 			props: {
 				orientation: () => this.separatorOrientation
 			},
-			owner: this,
-			syncAttrs: true
+			owner: this
 		});
 	}
 
diff --git a/src/uix/soma/components/tooltip/tooltip-provider.svelte.test.ts b/src/uix/soma/components/tooltip/tooltip-provider.svelte.test.ts
index bcf58d4b2..bb5774806 100644
--- a/src/uix/soma/components/tooltip/tooltip-provider.svelte.test.ts
+++ b/src/uix/soma/components/tooltip/tooltip-provider.svelte.test.ts
@@ -157,7 +157,8 @@ describe('TooltipProvider', () => {
 		expect(opts.open.current).toBe(true);
 		// Hover-delay path opens with the ENTRANCE state so the eidos animation plays.
 		expect(result.provider.tooltipState).toBe('delayed-open');
-		expect(triggerEl.getAttribute('data-state')).toBe('delayed-open');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.trigger.props['data-state']).toBe('delayed-open');
 
 		result.trigger.onpointerleave();
 		expect(harness.schedule).toHaveBeenCalledWith(
@@ -314,11 +315,12 @@ describe('TooltipProvider', () => {
 		expect(result.provider.contentId.current).toBe('tooltip-content');
 
 		await tick();
-		expect(triggerEl.getAttribute('aria-describedby')).toBe('tooltip-content');
-		expect(contentEl.getAttribute('role')).toBe('tooltip');
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
+		expect(result.trigger.props['aria-describedby']).toBe('tooltip-content');
+		expect(result.content.props['role']).toBe('tooltip');
 		// Naming default: ships in the render bag (consumerWins, A-85).
 		expect(result.content.props).toMatchObject({ 'aria-label': 'Helpful hint' });
-		expect(contentEl.getAttribute('data-state')).toBe('instant-open');
+		expect(result.content.props['data-state']).toBe('instant-open');
 
 		cleanup();
 		harness.dom.dispose();
diff --git a/src/uix/soma/components/tooltip/tooltip-provider.svelte.ts b/src/uix/soma/components/tooltip/tooltip-provider.svelte.ts
index e607ef504..fd6448c01 100644
--- a/src/uix/soma/components/tooltip/tooltip-provider.svelte.ts
+++ b/src/uix/soma/components/tooltip/tooltip-provider.svelte.ts
@@ -6,12 +6,7 @@ import {
 	type ActiveProps,
 	type StateProps
 } from '$libs/reactive';
-import type {
-	OnChangeFn,
-	Direction,
-	Arrayable,
-	StyleProperties
-} from '../../types';
+import type { OnChangeFn, Direction, Arrayable, StyleProperties } from '../../types';
 import { KEYS } from '../../keyboard';
 
 import { Presence } from '../../layers/presence.svelte';
@@ -348,8 +343,7 @@ export class TooltipTriggerProvider {
 			owner: this,
 			onRefChange: (el) => {
 				this.provider.triggerRef.current = el;
-			},
-			syncAttrs: true
+			}
 		});
 		this.provider.triggerId.current = opts.id.current;
 
@@ -452,8 +446,7 @@ export class TooltipContentProvider {
 			owner: this,
 			onRefChange: (el) => {
 				this.provider.setContentRef(el);
-			},
-			syncAttrs: true
+			}
 		});
 		this.provider.contentId.current = opts.id.current;
 
@@ -501,10 +494,7 @@ export class TooltipContentProvider {
 	readonly isPresent = $derived.by(() => this.provider.contentPresence.isPresent);
 
 	readonly wrapperProps = $derived.by(() =>
-		buildFloatingShellWrapperProps(
-			this.floating,
-			this.provider.hoverableDisabled ? 'none' : 'auto'
-		)
+		buildFloatingShellWrapperProps(this.floating, this.provider.hoverableDisabled ? 'none' : 'auto')
 	);
 
 	readonly onpointerenter = () => {
diff --git a/src/uix/soma/components/virtual-grid/virtual-grid-provider.svelte.ts b/src/uix/soma/components/virtual-grid/virtual-grid-provider.svelte.ts
index 0b31391cb..3f9b4b54c 100644
--- a/src/uix/soma/components/virtual-grid/virtual-grid-provider.svelte.ts
+++ b/src/uix/soma/components/virtual-grid/virtual-grid-provider.svelte.ts
@@ -214,7 +214,7 @@ export class VirtualGridProvider {
 
 	readonly props = $derived.by(() =>
 		this.runtimePart.assert({
-			...this.runtimePart.props,
+			...this.runtimePart.props
 			// Raw, never `resolvedDir`: the Cell anchors on `inset-inline-start` while its
 			// translate3d takes the sign from `resolvedDir` — both must read the same axis.
 		} as const)
@@ -258,7 +258,10 @@ export class VirtualGridViewportProvider {
 				// Morfo: commit-set-resize on `provider`. Only emit on real
 				// dimension change (ResizeObserver fires on every layout);
 				// skip the initial measurement (prevH === prevW === 0).
-				if ((prevH !== el.clientHeight || prevW !== el.clientWidth) && (prevH !== 0 || prevW !== 0)) {
+				if (
+					(prevH !== el.clientHeight || prevW !== el.clientWidth) &&
+					(prevH !== 0 || prevW !== 0)
+				) {
 					void this.provider.runtime.trigger('commit-set-resize');
 				}
 			};
@@ -338,8 +341,7 @@ export class VirtualGridCellProvider {
 			props: {
 				rowIndex: () => this.opts.rowIndex.current,
 				columnIndex: () => this.opts.columnIndex.current
-			},
-			syncAttrs: true
+			}
 		});
 	}
 
diff --git a/src/uix/soma/components/virtual-list/virtual-list-provider.svelte.ts b/src/uix/soma/components/virtual-list/virtual-list-provider.svelte.ts
index 3ef15d7b7..0b013cd49 100644
--- a/src/uix/soma/components/virtual-list/virtual-list-provider.svelte.ts
+++ b/src/uix/soma/components/virtual-list/virtual-list-provider.svelte.ts
@@ -98,8 +98,7 @@ export class VirtualListProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: VirtualListProvider.ctx,
-			syncAttrs: true
+			context: VirtualListProvider.ctx
 		});
 
 		// ── Anchor 'end' (chat mode) ─────────────────────────────────────────
@@ -502,7 +501,7 @@ export class VirtualListProvider {
 
 	readonly props = $derived.by(() =>
 		this.runtimePart.assert({
-			...this.runtimePart.props,
+			...this.runtimePart.props
 			// Raw, never `resolvedDir`: the Item anchors on `inset-inline-start` while its
 			// translate takes the sign from `resolvedDir` — both must read the same axis.
 		} as const)
@@ -531,8 +530,7 @@ export class VirtualListViewportProvider {
 			owner: this,
 			onRefChange: (el) => {
 				this.provider.viewportRef = el;
-			},
-			syncAttrs: true
+			}
 		});
 
 		$effect(() => {
@@ -628,8 +626,7 @@ export class VirtualListWindowViewportProvider {
 			owner: this,
 			onRefChange: (el) => {
 				this.provider.windowHostRef = el;
-			},
-			syncAttrs: true
+			}
 		});
 
 		$effect(() => {
@@ -718,8 +715,7 @@ export class VirtualListItemProvider {
 			props: {
 				index: () => this.opts.index.current,
 				orientation: () => this.provider.opts.orientation.current
-			},
-			syncAttrs: true
+			}
 		});
 
 		// ResizeObserver: report real rendered size back to the provider so
@@ -780,9 +776,7 @@ export class VirtualListItemProvider {
 				position: 'absolute',
 				insetBlockStart: '0',
 				insetInlineStart: '0',
-				transform: horizontal
-					? `translateX(${rtl ? -start : start}px)`
-					: `translateY(${start}px)`,
+				transform: horizontal ? `translateX(${rtl ? -start : start}px)` : `translateY(${start}px)`,
 				...sizeStyle
 			}
 		} as const);
diff --git a/src/uix/soma/components/waveform/waveform-provider.svelte.test.ts b/src/uix/soma/components/waveform/waveform-provider.svelte.test.ts
index f5c11f75c..0fa117b5e 100644
--- a/src/uix/soma/components/waveform/waveform-provider.svelte.test.ts
+++ b/src/uix/soma/components/waveform/waveform-provider.svelte.test.ts
@@ -64,22 +64,19 @@ describe('WaveformProvider', () => {
 		document.body.innerHTML = '';
 	});
 
-	it('exposes the provider contract and the bar geometry', async () => {
+	it('exposes the provider contract and the bar geometry', () => {
 		installSomaHarness();
 		const root = document.createElement('div');
 		const opts = waveformOpts(root);
 
 		const { result: provider, cleanup } = withEffectRoot(() => WaveformProvider.create(opts));
 
+		// Bag assert — fase C2c retired the syncAttrs effect (P0, audit 2026-08-26); this test renders nothing.
 		expect(provider.props).toMatchObject({
 			id: 'waveform',
-			'data-waveform': ''
+			'data-waveform': '',
+			'data-shape': 'bars'
 		});
-		// Morfo-declared reactive data lands on the ELEMENT via syncAttrs —
-		// wait for the runtime to apply it before measuring.
-		const { tick } = await import('svelte');
-		await tick();
-		expect(root.getAttribute('data-shape')).toBe('bars');
 		// Two peaks → two vertical strokes. Silence paints the perceptual FLOOR
 		// (a thin line, the SoundCloud reading), a full peak spans the AMP.
 		expect(provider.wavePath).toBe('M25.00 15.5V16.5M75.00 1V31');
diff --git a/src/uix/soma/components/waveform/waveform-provider.svelte.ts b/src/uix/soma/components/waveform/waveform-provider.svelte.ts
index 2002d2b36..f38b19fb5 100644
--- a/src/uix/soma/components/waveform/waveform-provider.svelte.ts
+++ b/src/uix/soma/components/waveform/waveform-provider.svelte.ts
@@ -106,8 +106,7 @@ export class WaveformProvider {
 			id: opts.id,
 			ref: opts.ref,
 			owner: this,
-			context: WaveformProvider.ctx,
-			syncAttrs: true
+			context: WaveformProvider.ctx
 		});
 	}
 
diff --git a/src/uix/soma/runtime.svelte.test.ts b/src/uix/soma/runtime.svelte.test.ts
index ba684fc39..1c4ec321a 100644
--- a/src/uix/soma/runtime.svelte.test.ts
+++ b/src/uix/soma/runtime.svelte.test.ts
@@ -26,11 +26,12 @@ import { drawerMorfo } from '@/uix/morfo/components/drawer';
 import { popoverMorfo } from '@/uix/morfo/components/popover';
 import { floatPanelMorfo } from '@/uix/morfo/components/float-panel';
 import { createSomaRuntime, type EventEngineEmitter } from './runtime.svelte';
+import { mergeProps } from './props';
 
 /**
  * Effect roots are normally provided by Svelte components. For unit tests we
  * wrap the runtime construction in `$effect.root` so `$effect` calls inside
- * `part(..., { syncAttrs: true })` have a parent to attach to.
+ * `part(...)` (attachments, context) have a parent to attach to.
  */
 function withEffectRoot<T>(fn: () => T): { result: T; cleanup: () => void } {
 	let result!: T;
@@ -70,7 +71,7 @@ describe('createSomaRuntime', () => {
 				dom,
 				states: { on: () => false }
 			});
-			r.part('provider', { id, ref, syncAttrs: true });
+			r.part('provider', { id, ref });
 			return r;
 		});
 
@@ -160,46 +161,24 @@ describe('createSomaRuntime', () => {
 				}
 			]
 		} as const;
-		const ref = state<HTMLElement | null>(null);
-
-		const { cleanup } = withEffectRoot(() => {
+		const { result: handle, cleanup } = withEffectRoot(() => {
 			const r = createSomaRuntime(partRefMorfo, { dom });
-			r.part('trigger', {
+			return r.part('trigger', {
 				id: state('trigger-1'),
-				ref,
-				parts: { content: () => 'content-1' },
-				syncAttrs: true
-			});
-		});
-
-		ref.current = target;
-		flushSync();
-
-		expect(target.getAttribute('aria-controls')).toBe('content-1');
-		cleanup();
-	});
-
-	it('part can opt into runtime DOM attr synchronization', () => {
-		const ref = state<HTMLElement | null>(null);
-		const { cleanup } = withEffectRoot(() => {
-			const id = state('tog-1');
-			const r = createSomaRuntime(toggleMorfo, {
-				dom,
-				states: { on: () => false }
+				parts: { content: () => 'content-1' }
 			});
-			r.part('provider', { id, ref, syncAttrs: true });
 		});
 
-		ref.current = target;
-		flushSync();
-
-		expect(target.getAttribute('data-state')).toBe('off');
+		expect(handle.props['aria-controls']).toBe('content-1');
 		cleanup();
 	});
 
-	it('writes morfo-derived attrs to DOM when ref attaches', () => {
-		const ref = state<HTMLElement | null>(null);
-		const { cleanup } = withEffectRoot(() => {
+	it('the bag resolves the full contract and omits undefined-valued plans', () => {
+		// Re-signed for fase C2c (P0, audit 2026-08-26): the old pair of tests
+		// here exercised the retired `syncAttrs` effect (DOM writes on ref
+		// attach). The render bag is the single pipeline now — the same
+		// resolution, asserted on the bag Svelte spreads.
+		const { result: handle, cleanup } = withEffectRoot(() => {
 			const id = state('tog-1');
 			const r = createSomaRuntime(toggleMorfo, {
 				dom,
@@ -212,29 +191,25 @@ describe('createSomaRuntime', () => {
 					ariaLabel: () => undefined
 				}
 			});
-			r.part('provider', { id, ref, syncAttrs: true });
+			return r.part('provider', { id });
 		});
 
-		// Simulate Svelte's attachment firing — the runtime registered a setter
-		// on the ref via attachRef, but in tests we mutate the ref directly.
-		ref.current = target;
-		flushSync();
-
-		expect(target.getAttribute('data-state')).toBe('off');
-		expect(target.getAttribute('aria-pressed')).toBe('false');
-		expect(target.getAttribute('type')).toBe('button');
-		expect(target.hasAttribute('data-disabled')).toBe(false);
-		expect(target.hasAttribute('aria-disabled')).toBe(false);
+		const props = handle.props;
+		expect(props['data-state']).toBe('off');
+		expect(props['aria-pressed']).toBe('false');
+		expect(props['type']).toBe('button');
+		expect('data-disabled' in props).toBe(false);
+		expect('aria-disabled' in props).toBe(false);
 		cleanup();
 	});
 
-	it('ships naming defaults in the bag, never through dom.apply (A-85)', () => {
+	it('naming defaults stay consumer-first in the bag (A-85)', () => {
 		// Two-class precedence: `aria-label` with a fixed text source is a
-		// NAMING DEFAULT — the render bag carries it (mergeProps resolves it
-		// consumer-first) and the syncAttrs effect must NOT write it, or the
-		// post-render dom.apply would overwrite the consumer's own label on
-		// every pass. Contract attrs (`aria-expanded`) keep flowing via the
-		// effect.
+		// NAMING DEFAULT — the render bag carries it and `mergeProps` resolves
+		// it consumer-first. With the syncAttrs effect retired (fase C2c) no
+		// post-render dom.apply exists to overwrite the consumer's label; the
+		// invariant left to pin is the bag's content per class: contract attrs
+		// resolved, naming defaults present but yielding through mergeProps.
 		const namingMorfo = {
 			name: 'NamingFixture',
 			kebab: 'naming-fixture',
@@ -257,11 +232,6 @@ describe('createSomaRuntime', () => {
 			]
 		} as const;
 
-		// The consumer rendered their own label; Svelte put it in the DOM
-		// before the runtime's effect ran.
-		target.setAttribute('aria-label', 'Consumer label');
-
-		const ref = state<HTMLElement | null>(null);
 		const open = state(false);
 		const { result: handle, cleanup } = withEffectRoot(() => {
 			const r = createSomaRuntime(namingMorfo, {
@@ -269,33 +239,34 @@ describe('createSomaRuntime', () => {
 				states: { open: () => open.current },
 				translate: () => 'Abrir cosa'
 			});
-			return r.part('trigger', { id: state('nf-1'), ref, syncAttrs: true });
+			return r.part('trigger', { id: state('nf-1') });
 		});
 
-		ref.current = target;
-		flushSync();
-
 		// The bag carries the resolved default (locale-reactive: `translate`
-		// runs inside the composing $derived)…
+		// runs inside the composing $derived) AND the contract attr…
 		expect(handle.props['aria-label']).toBe('Abrir cosa');
-		// …the effect wrote the contract attr but left the consumer's label
-		// alone…
-		expect(target.getAttribute('aria-expanded')).toBe('false');
-		expect(target.getAttribute('aria-label')).toBe('Consumer label');
+		expect(handle.props['aria-expanded']).toBe('false');
+
+		// …the consumer's own label wins through mergeProps (naming attrs are
+		// `consumerWins`: consumer-first, unlike contract attrs)…
+		const merged = mergeProps({ 'aria-label': 'Consumer label' }, handle.props);
+		expect(merged['aria-label']).toBe('Consumer label');
 
-		// …and a state-driven re-run still does not touch it.
+		// …and a state-driven re-read refreshes the contract without ever
+		// producing a writer that could clobber the consumer's label.
 		open.current = true;
 		flushSync();
-		expect(target.getAttribute('aria-expanded')).toBe('true');
-		expect(target.getAttribute('aria-label')).toBe('Consumer label');
+		expect(handle.props['aria-expanded']).toBe('true');
+		expect(mergeProps({ 'aria-label': 'Consumer label' }, handle.props)['aria-label']).toBe(
+			'Consumer label'
+		);
 		cleanup();
 	});
 
-	it('reapplies attrs when sources change', () => {
-		const ref = state<HTMLElement | null>(null);
+	it('the bag re-derives when sources change', () => {
 		const pressed = state(false);
 		const disabled = state(false);
-		const { cleanup } = withEffectRoot(() => {
+		const { result: handle, cleanup } = withEffectRoot(() => {
 			const id = state('tog-1');
 			const r = createSomaRuntime(toggleMorfo, {
 				dom,
@@ -308,28 +279,25 @@ describe('createSomaRuntime', () => {
 					ariaLabel: () => undefined
 				}
 			});
-			r.part('provider', { id, ref, syncAttrs: true });
+			return r.part('provider', { id });
 		});
 
-		ref.current = target;
-		flushSync();
-		expect(target.getAttribute('data-state')).toBe('off');
+		expect(handle.props['data-state']).toBe('off');
 
 		pressed.current = true;
 		flushSync();
-		expect(target.getAttribute('data-state')).toBe('on');
-		expect(target.getAttribute('aria-pressed')).toBe('true');
+		expect(handle.props['data-state']).toBe('on');
+		expect(handle.props['aria-pressed']).toBe('true');
 
 		disabled.current = true;
 		flushSync();
-		expect(target.getAttribute('aria-disabled')).toBe('true');
+		expect(handle.props['aria-disabled']).toBe('true');
 		cleanup();
 	});
 
-	it('removes conditional attrs when their condition flips back to false', () => {
-		const ref = state<HTMLElement | null>(null);
+	it('conditional attrs leave the bag when their condition flips back to false', () => {
 		const invalid = state(false);
-		const { cleanup } = withEffectRoot(() => {
+		const { result: handle, cleanup } = withEffectRoot(() => {
 			const id = state('tog-1');
 			const r = createSomaRuntime(toggleMorfo, {
 				dom,
@@ -342,32 +310,29 @@ describe('createSomaRuntime', () => {
 					ariaLabel: () => undefined
 				}
 			});
-			r.part('provider', { id, ref, syncAttrs: true });
+			return r.part('provider', { id });
 		});
 
-		ref.current = target;
-		flushSync();
-		expect(target.hasAttribute('data-invalid')).toBe(false);
-		expect(target.hasAttribute('aria-invalid')).toBe(false);
+		expect('data-invalid' in handle.props).toBe(false);
+		expect('aria-invalid' in handle.props).toBe(false);
 
 		invalid.current = true;
 		flushSync();
-		expect(target.getAttribute('data-invalid')).toBe('');
-		expect(target.getAttribute('aria-invalid')).toBe('true');
+		expect(handle.props['data-invalid']).toBe('');
+		expect(handle.props['aria-invalid']).toBe('true');
 
 		invalid.current = false;
 		flushSync();
-		expect(target.hasAttribute('data-invalid')).toBe(false);
-		expect(target.hasAttribute('aria-invalid')).toBe(false);
+		expect('data-invalid' in handle.props).toBe(false);
+		expect('aria-invalid' in handle.props).toBe(false);
 		cleanup();
 	});
 
-	it('writes non-enum data attrs as raw values when morfo declares emit:value', () => {
-		const ref = state<HTMLElement | null>(null);
+	it('resolves non-enum data attrs as raw values when morfo declares emit:value', () => {
 		const value = state<number | null>(20);
 		const min = state(0);
 		const max = state(100);
-		const { cleanup } = withEffectRoot(() => {
+		const { result: handle, cleanup } = withEffectRoot(() => {
 			const id = state('progress-1');
 			const r = createSomaRuntime(progressMorfo, {
 				dom,
@@ -381,23 +346,23 @@ describe('createSomaRuntime', () => {
 					ariaLabelledby: () => undefined
 				}
 			});
-			r.part('provider', { id, ref, syncAttrs: true });
+			return r.part('provider', { id });
 		});
 
-		ref.current = target;
-		flushSync();
-
-		expect(target.getAttribute('data-value')).toBe('20');
-		expect(target.getAttribute('data-min')).toBe('0');
-		expect(target.getAttribute('data-max')).toBe('100');
+		// The bag hands the RAW resolved value; Svelte stringifies at render, so
+		// the DOM output is identical to what dom.apply used to write. (The old
+		// DOM-read assertions saw '20' for that reason.)
+		expect(handle.props['data-value']).toBe(20);
+		expect(handle.props['data-min']).toBe(0);
+		expect(handle.props['data-max']).toBe(100);
 
 		value.current = null;
 		flushSync();
 
-		expect(target.hasAttribute('data-value')).toBe(false);
-		expect(target.getAttribute('data-state')).toBe('indeterminate');
-		expect(target.getAttribute('data-min')).toBe('0');
-		expect(target.getAttribute('data-max')).toBe('100');
+		expect('data-value' in handle.props).toBe(false);
+		expect(handle.props['data-state']).toBe('indeterminate');
+		expect(handle.props['data-min']).toBe(0);
+		expect(handle.props['data-max']).toBe(100);
 		cleanup();
 	});
 
@@ -433,7 +398,7 @@ describe('createSomaRuntime', () => {
 		} as const;
 		const { result, cleanup } = withEffectRoot(() => {
 			const r = createSomaRuntime(archetypedMorfo, { dom });
-			r.part('provider', { id: state('p-1'), syncAttrs: true });
+			r.part('provider', { id: state('p-1') });
 			return r;
 		});
 
@@ -463,7 +428,7 @@ describe('createSomaRuntime', () => {
 		} as const;
 		const { result, cleanup } = withEffectRoot(() => {
 			const r = createSomaRuntime(archetypeless, { dom });
-			r.part('provider', { id: state('p-1'), syncAttrs: true });
+			r.part('provider', { id: state('p-1') });
 			return r;
 		});
 
@@ -578,7 +543,7 @@ describe('runtime.trigger', () => {
 					intent: () => 'risk'
 				}
 			});
-			r.part('item', { id: state('toast-1'), ref: itemRef, syncAttrs: true });
+			r.part('item', { id: state('toast-1'), ref: itemRef });
 			itemRef.current = item;
 			void r.trigger('signal-announce');
 		});
@@ -733,7 +698,7 @@ describe('runtime.trigger', () => {
 				eventEngine: sem.engine,
 				props: {}
 			});
-			r.part('item', { id: state('toast-1'), ref: itemRef, syncAttrs: true });
+			r.part('item', { id: state('toast-1'), ref: itemRef });
 			itemRef.current = item;
 			void r.trigger('signal-announce');
 		});
@@ -843,7 +808,7 @@ describe('runtime.trigger', () => {
 		const itemRef = state<HTMLElement | null>(null);
 		const { cleanup } = withEffectRoot(() => {
 			const r = createSomaRuntime(toastMorfo, { dom, eventEngine: sem.engine });
-			r.part('item', { id: state('toast-1'), ref: itemRef, syncAttrs: true });
+			r.part('item', { id: state('toast-1'), ref: itemRef });
 			itemRef.current = item;
 			void r.trigger('signal-announce');
 		});
@@ -864,7 +829,7 @@ describe('runtime.trigger', () => {
 		const itemRef = state<HTMLElement | null>(null);
 		const { cleanup } = withEffectRoot(() => {
 			const r = createSomaRuntime(morfo, { dom, eventEngine: sem.engine });
-			r.part('item', { id: state('toast-1'), ref: itemRef, syncAttrs: true });
+			r.part('item', { id: state('toast-1'), ref: itemRef });
 			itemRef.current = item;
 			void r.trigger('signal-announce');
 		});
@@ -885,7 +850,7 @@ describe('runtime.trigger', () => {
 		const itemRef = state<HTMLElement | null>(null);
 		const { cleanup } = withEffectRoot(() => {
 			const r = createSomaRuntime(morfo, { dom, eventEngine: sem.engine });
-			r.part('item', { id: state('toast-1'), ref: itemRef, syncAttrs: true });
+			r.part('item', { id: state('toast-1'), ref: itemRef });
 			itemRef.current = item;
 			void r.trigger('signal-announce');
 		});
@@ -903,7 +868,7 @@ describe('runtime.trigger', () => {
 				dom,
 				eventEngine: sem.engine
 			});
-			r.part('item', { id: state('toast-1'), ref: itemRef, syncAttrs: true });
+			r.part('item', { id: state('toast-1'), ref: itemRef });
 			itemRef.current = item;
 			void r.trigger('emerge-present');
 		});
@@ -929,7 +894,7 @@ describe('runtime.trigger', () => {
 				eventEngine: sem.engine,
 				states: { open: () => true }
 			});
-			r.part('content', { id: state('fx-1'), ref: contentRef, syncAttrs: true });
+			r.part('content', { id: state('fx-1'), ref: contentRef });
 			contentRef.current = content;
 			void r.trigger('emerge-close-cancel');
 		});
@@ -953,7 +918,7 @@ describe('runtime.trigger', () => {
 				eventEngine: sem.engine,
 				events: { 'emerge-dismiss': handler }
 			});
-			r.part('item', { id: state('toast-1'), ref: itemRef, syncAttrs: true });
+			r.part('item', { id: state('toast-1'), ref: itemRef });
 			itemRef.current = item;
 			void r.trigger('emerge-dismiss');
 		});
@@ -976,7 +941,7 @@ describe('runtime.trigger', () => {
 				dom,
 				events: { 'emerge-dismiss': handler }
 			});
-			r.part('item', { id: state('toast-1'), ref: itemRef, syncAttrs: true });
+			r.part('item', { id: state('toast-1'), ref: itemRef });
 			itemRef.current = item;
 			void r.trigger('emerge-dismiss');
 		});
@@ -1003,7 +968,7 @@ describe('runtime.trigger', () => {
 		const itemRef = state<HTMLElement | null>(null);
 		const { result, cleanup } = withEffectRoot(() => {
 			const r = createSomaRuntime(morfo, { dom, eventEngine: sem.engine });
-			r.part('item', { id: state('toast-1'), ref: itemRef, syncAttrs: true });
+			r.part('item', { id: state('toast-1'), ref: itemRef });
 			itemRef.current = item;
 			return r.trigger('signal-announce');
 		});
@@ -1020,7 +985,7 @@ describe('runtime.trigger', () => {
 		const itemRef = state<HTMLElement | null>(null);
 		const { result, cleanup } = withEffectRoot(() => {
 			const r = createSomaRuntime(toastMorfo, { dom, eventEngine: sem.engine });
-			r.part('item', { id: state('toast-1'), ref: itemRef, syncAttrs: true });
+			r.part('item', { id: state('toast-1'), ref: itemRef });
 			itemRef.current = item;
 			return r.trigger('signal-announce');
 		});
@@ -1044,7 +1009,7 @@ describe('runtime.trigger', () => {
 		const itemRef = state<HTMLElement | null>(null);
 		const { cleanup } = withEffectRoot(() => {
 			const r = createSomaRuntime(morfo, { dom, eventEngine: sem.engine });
-			r.part('item', { id: state('toast-1'), ref: itemRef, syncAttrs: true });
+			r.part('item', { id: state('toast-1'), ref: itemRef });
 			itemRef.current = item;
 			void r.trigger('signal-announce', { persistence: 'untilFix' });
 		});
@@ -1077,7 +1042,7 @@ describe('runtime.trigger', () => {
 		const itemRef = state<HTMLElement | null>(null);
 		const { cleanup } = withEffectRoot(() => {
 			const r = createSomaRuntime(morfo, { dom, eventEngine: sem.engine });
-			r.part('item', { id: state('toast-1'), ref: itemRef, syncAttrs: true });
+			r.part('item', { id: state('toast-1'), ref: itemRef });
 			itemRef.current = item;
 			void r.trigger('signal-announce');
 		});
@@ -1106,7 +1071,7 @@ describe('runtime.trigger', () => {
 		const itemRef = state<HTMLElement | null>(null);
 		const { cleanup } = withEffectRoot(() => {
 			const r = createSomaRuntime(morfo, { dom, eventEngine: sem.engine });
-			r.part('item', { id: state('toast-1'), ref: itemRef, syncAttrs: true });
+			r.part('item', { id: state('toast-1'), ref: itemRef });
 			itemRef.current = item;
 			void r.trigger('signal-announce', {
 				semantic: { family: 'commit', verb: 'discard', intent: 'loss' }
@@ -1137,7 +1102,7 @@ describe('runtime.trigger', () => {
 		const itemRef = state<HTMLElement | null>(null);
 		const { result, cleanup } = withEffectRoot(() => {
 			const r = createSomaRuntime(morfo, { dom, eventEngine: sem.engine });
-			r.part('item', { id: state('toast-1'), ref: itemRef, syncAttrs: true });
+			r.part('item', { id: state('toast-1'), ref: itemRef });
 			itemRef.current = item;
 			return r.trigger('signal-announce', {
 				// `shift` is NOT in allowedFamilies and isn't the default — should raise.
@@ -1172,7 +1137,7 @@ describe('runtime.trigger', () => {
 		const itemRef = state<HTMLElement | null>(null);
 		const { cleanup } = withEffectRoot(() => {
 			const r = createSomaRuntime(morfo, { dom, eventEngine: sem.engine });
-			r.part('item', { id: state('toast-1'), ref: itemRef, syncAttrs: true });
+			r.part('item', { id: state('toast-1'), ref: itemRef });
 			itemRef.current = item;
 			void r.trigger('signal-announce', {
 				semantic: { family: 'signal', verb: 'announce', intent: 'risk' }
@@ -1213,7 +1178,7 @@ describe('runtime.keydown', () => {
 	it('returns false when the part has no keyboard declarations', () => {
 		const { result, cleanup } = withEffectRoot(() => {
 			const r = createSomaRuntime(toggleMorfo, { dom });
-			r.part('provider', { id: state('t-1'), syncAttrs: true });
+			r.part('provider', { id: state('t-1') });
 			return r;
 		});
 
@@ -1229,7 +1194,7 @@ describe('runtime.keydown', () => {
 				dir: state<Direction | undefined>(undefined),
 				actions: { toggle: handler }
 			});
-			r.part('provider', { id: state('sw-1'), syncAttrs: true });
+			r.part('provider', { id: state('sw-1') });
 			return r;
 		});
 
@@ -1248,7 +1213,7 @@ describe('runtime.keydown', () => {
 				dir: state<Direction | undefined>(undefined),
 				actions: { toggle: handler }
 			});
-			r.part('provider', { id: state('sw-1'), syncAttrs: true });
+			r.part('provider', { id: state('sw-1') });
 			return r;
 		});
 
@@ -1266,7 +1231,7 @@ describe('runtime.keydown', () => {
 				dir: state<Direction | undefined>(undefined),
 				actions: { toggle: handler }
 			});
-			r.part('provider', { id: state('sw-1'), syncAttrs: true });
+			r.part('provider', { id: state('sw-1') });
 			return r;
 		});
 
@@ -1290,7 +1255,7 @@ describe('runtime.keydown', () => {
 					close: vi.fn()
 				}
 			});
-			r.part('content', { id: state('d-1'), syncAttrs: true });
+			r.part('content', { id: state('d-1') });
 			return r;
 		});
 
@@ -1311,7 +1276,7 @@ describe('runtime.keydown', () => {
 				dir: state<Direction | undefined>(undefined),
 				actions: {} // no `toggle` handler
 			});
-			r.part('provider', { id: state('sw-1'), syncAttrs: true });
+			r.part('provider', { id: state('sw-1') });
 			return r;
 		});
 
@@ -1330,7 +1295,7 @@ describe('runtime.keydown', () => {
 				dir: state<Direction | undefined>(undefined),
 				actions: { toggle: handler }
 			});
-			r.part('provider', { id: state('sw-1'), syncAttrs: true });
+			r.part('provider', { id: state('sw-1') });
 			return r;
 		});
 
diff --git a/src/uix/soma/runtime.svelte.ts b/src/uix/soma/runtime.svelte.ts
index ea932ad91..481972e30 100644
--- a/src/uix/soma/runtime.svelte.ts
+++ b/src/uix/soma/runtime.svelte.ts
@@ -14,29 +14,22 @@
  * Surface:
  * - `part(part, opts)` — high-level part handle for concrete provider
  *   classes: registration, context publication, the render bag and contract
- *   helpers. When `syncAttrs` is true, the runtime additionally re-asserts
- *   the part's morfo-derived DOM attrs through `dom.apply`.
+ *   helpers.
  * - `partProps(part)` — the FULL render bag (P0 fase C, audit 2026-08-26):
  *   static identity (id, marker, ref attachment, dir) plus the resolved morfo
  *   contract — `staticAttrs` (role, literals) and every dynamic plan. It is
- *   the single attr pipeline: the same values server-render and re-derive
+ *   the SINGLE attr pipeline: the same values server-render and re-derive
  *   through Svelte's reactivity. Before the unification the bag carried
- *   identity only and the contract lived in a client-only effect, so 42
- *   providers server-rendered with no role / aria-* / data-state.
+ *   identity only and the contract lived in a client-only `syncAttrs` effect
+ *   (retired in fase C2c), so 42 providers server-rendered with no role /
+ *   aria-* / data-state.
  * - `keydown(part, event)` — dispatch from `morfo.keyboard`.
  * - `trigger(eventName)` — orchestrates prewrite + eventEngine.emit + handler.
  *
  * Operational rules:
- * - The render bag and the `syncAttrs` effect resolve the SAME plans from the
- *   same bindings, so a double write is idempotent by construction. The
- *   effect survives for imperative re-assertion (prewrites, non-render
- *   consumers) until fase C2c retires it.
- * - `part(..., { syncAttrs: true })` must be called inside an effect root
- *   (a Svelte component scope or a class constructor invoked during component
- *   init), because the per-part effect uses `$effect`.
- * - Effects are best-effort idempotent: each tick reapplies the full attr
- *   map for that part. Missing attrs are removed via `dom.apply`'s
- *   `false/null/undefined` handling.
+ * - Nothing writes a part's contract attrs outside the render bag. The one
+ *   sanctioned imperative writer left is `trigger`'s prewrite (a commit the
+ *   morfo declares), which goes through `dom.apply` on its own step.
  *
  * Sema is ornamental:
  * - `sources.eventEngine` is OPTIONAL. If absent, `trigger` runs prewrite +
@@ -218,12 +211,6 @@ export interface SomaRuntimePartOpts<Owner = unknown> extends SomaRuntimePartBas
 	owner?: Owner;
 	/** Optional context where the provider instance should be registered. */
 	context?: SomaRuntimePartContext<Owner>;
-	/**
-	 * When true, this part's morfo attrs are synchronized to the DOM by the
-	 * runtime effect. Keep false for providers that still author their
-	 * state-derived attrs in render props.
-	 */
-	syncAttrs?: boolean;
 }
 
 /**
@@ -320,8 +307,8 @@ export interface SomaRuntime<M extends Morfo> {
 	 *      `data-last-action`)
 	 *   2. await `eventEngine.emit({ target, name, family, intent? })`
 	 *   3. invoke the provider's handler from `sources.events[name]`
-	 *   4. effects on the affected parts re-derive structural attrs from the
-	 *      new state and write them via `dom.apply` (automatic)
+	 *   4. the render bag re-derives structural attrs from the new state and
+	 *      Svelte re-renders them (automatic)
 	 *
 	 * Step 2 is skipped when `sources.eventEngine` is absent. Step 3 is skipped
 	 * when no handler is registered for the event.
@@ -636,41 +623,12 @@ export function createSomaRuntime<M extends Morfo>(
 		return bucket[bucket.length - 1];
 	}
 
-	function syncPartAttrs(reg: PartRegistration, compiledPart: CompiledPart): void {
-		// Effect: whenever the part's ref attaches OR any source changes,
-		// recompute the morfo-derived attrs and write them via dom.apply.
-		// Reading `reg.ref.current` is the reactive subscription point — the
-		// `attachRef` setter mutates it when Svelte's attachment callback fires.
-		//
-		// `staticAttrs` are pre-resolved at compile time (literals + role) and
-		// applied unconditionally; `dynamicAttrs` is the slice that requires
-		// per-tick evaluation against the bindings.
-		$effect(() => {
-			const target = reg.ref ? reg.ref.current : null;
-			if (!target) return;
-			const bindings = readBindings(reg, sources);
-			const resolved: Record<string, unknown> = { ...compiledPart.staticAttrs };
-			for (const plan of compiledPart.dynamicAttrs) {
-				// Naming defaults (`consumerWins`) never travel through dom.apply:
-				// this effect runs AFTER Svelte renders the consumer's attrs, so
-				// writing here would overwrite the consumer's own label on every
-				// pass (A-85). They ship in the render bag instead — see
-				// `partPropsForRegistration` — where mergeProps resolves them
-				// consumer-first.
-				if (plan.consumerWins) continue;
-				resolved[plan.attr] = evalAttrPlan(plan, bindings);
-			}
-			sources.dom.apply({ target, attrs: resolved as Record<string, DomAttrValue> });
-		});
-	}
-
 	function part<Owner = unknown>(
 		partName: string,
 		opts: SomaRuntimePartOpts<Owner>
 	): SomaRuntimePart<M, PartKebabOf<M>> {
 		const compiledPart = resolvePart(partName);
 		const reg = createRegistration(partName, opts);
-		if (opts.syncAttrs) syncPartAttrs(reg, compiledPart);
 		if (opts.context && opts.owner !== undefined) opts.context.set(opts.owner);
 
 		return {
@@ -763,11 +721,11 @@ export function createSomaRuntime<M extends Morfo>(
 		}
 
 		// Naming defaults (`consumerWins` plans — `aria-label`) go LAST and are
-		// the only plans `mergeProps` resolves consumer-first. Writing them from
-		// the syncAttrs effect instead would overwrite the consumer's attr after
-		// every render — the A-85 class. Reads are reactive: `translate` is
-		// `langs.ts()` (rune-backed locale), so the default re-renders on locale
-		// change.
+		// the only plans `mergeProps` resolves consumer-first. An imperative
+		// post-render writer would overwrite the consumer's attr on every pass —
+		// the A-85 class the retired syncAttrs effect had to tiptoe around.
+		// Reads are reactive: `translate` is `langs.ts()` (rune-backed locale),
+		// so the default re-renders on locale change.
 		for (const plan of reg.meta.dynamicAttrs) {
 			if (!plan.consumerWins) continue;
 			bindings ??= readBindings(reg, sources);
@@ -1146,9 +1104,9 @@ export function createSomaRuntime<M extends Morfo>(
 		// reflects the resolved outcome (handler may have flipped state).
 		runA11y();
 
-		// 5. Effects on the affected parts re-derive structural attrs from the
-		// new state and write them via `dom.apply` automatically — no explicit
-		// step here. State is the source of truth; the DOM is its derivation.
+		// 5. The render bag re-derives structural attrs from the new state and
+		// Svelte re-renders them automatically — no explicit step here. State
+		// is the source of truth; the DOM is its derivation.
 
 		return {
 			...(emittedId !== undefined ? { id: emittedId } : {}),