soma: Avatar migrated to runtime + V2 props bridge

First component of the bulk migration phase (step 2 of the 1-3-2 plan).
Pattern is now well-rehearsed across Toggle / Collapsible / Toast / Switch:
  - morfo: add `value` sources to data entries that were enum-only
  - provider: replace manual Opts interface with `OptsFromProps<...>`,
    create runtime in constructor, register parts, drop manual data-* /
    aria attrs from props (runtime emits via dom.apply)
  - wrapper: replace per-prop `readableActive(() => x)` list with one
    `bindProps({ ... })` call
  - keep manual: HTML primitives (style, src, etc.) and event handlers

Avatar specifics
- 3 parts (provider/image/fallback) all share `data-status` from the root's
  internal `status` State (idle/loading/loaded/error). morfo's `propRef('status')`
  reads from runtime sources where the root provider exposes it.
- `status` is not a public Props field — it's an internal $state in the
  wrapper. Manually intersected into `AvatarOpts` rather than derived from
  AvatarProps.
- Image's preload logic, src/crossorigin/referrerpolicy passthrough, and
  the style-based show/hide on each part stay in the provider's render —
  none of these are morfo-managed.
- Wrapper cast uses `as unknown as Parameters<typeof X.create>[0]` for
  parts whose Opts have only `id`+`ref` (TS can't extract the specific
  fields from the generic `Record<string, Active<unknown>>` return of
  `bindProps`). Toggle/Switch don't need this because their richer Opts
  shape provides enough overlap.

Bulk migration paused at this point — Progress / Meter need a design
decision around `aria-label` priority logic (the legacy provider has
"consumer-passed wins over translated default", which conflicts with the
"dom.apply is the only writer of mutable attrs" rule). Either:
  (a) Drop aria-label from those morfos and keep provider-managed (legacy
      pattern preserved, morfo loses one declaration).
  (b) Extend the resolver with a priority chain (propRef → translationRef
      fallback) so the morfo can express "consumer wins, translation
      otherwise".

Verification
- 66/66 morfo-check (Avatar passes; all data-status emitted by runtime).
- 68/68 smoke routes.
- svelte-check unchanged at 155.

src/uix/morfo/components/avatar.ts

@@ -1,4 +1,5 @@
 import type { Morfo } from '../types';
+import { v } from '../types';
 
 export const avatarMorfo = {
 	name: 'Avatar',
@@ -11,7 +12,13 @@ export const avatarMorfo = {
 			kind: 'public',
 			defaultElement: 'span',
 			optional: false,
-			data: [{ attr: 'data-status', values: ['idle', 'loading', 'loaded', 'error'] }],
+			data: [
+				{
+					attr: 'data-status',
+					values: ['idle', 'loading', 'loaded', 'error'],
+					value: v.propRef('status')
+				}
+			],
 			aria: []
 		},
 		{
@@ -20,7 +27,13 @@ export const avatarMorfo = {
 			kind: 'public',
 			defaultElement: 'img',
 			optional: false,
-			data: [{ attr: 'data-status', values: ['idle', 'loading', 'loaded', 'error'] }],
+			data: [
+				{
+					attr: 'data-status',
+					values: ['idle', 'loading', 'loaded', 'error'],
+					value: v.propRef('status')
+				}
+			],
 			aria: []
 		},
 		{
@@ -29,7 +42,13 @@ export const avatarMorfo = {
 			kind: 'public',
 			defaultElement: 'span',
 			optional: false,
-			data: [{ attr: 'data-status', values: ['idle', 'loading', 'loaded', 'error'] }],
+			data: [
+				{
+					attr: 'data-status',
+					values: ['idle', 'loading', 'loaded', 'error'],
+					value: v.propRef('status')
+				}
+			],
 			aria: []
 		}
 	]

src/uix/soma/components/avatar/avatar-provider.svelte.ts

@@ -1,14 +1,16 @@
 import { watch } from 'runed';
 import { Provider, context, type WithRefOpts } from '../../provider';
 import { createAttrs, registerContract } from '../../attrs';
-import { state, type ActiveProps, type StateProps } from '../../reactive';
+import type { OptsFromProps, State } from '../../reactive';
 import type { OnChangeFn } from '../../types';
+import { Soma } from '../../core/soma.svelte';
+import { createMorfoRuntime, type MorfoRuntime } from '../../morfo';
 import type { HTMLImgAttributes } from 'svelte/elements';
-import type { AvatarLoadingStatus } from './types';
+import type { AvatarLoadingStatus, AvatarProps, AvatarImageProps } from './types';
 
 import { avatarMorfo } from '../../../morfo/components/avatar';
 
-const attrs = createAttrs(avatarMorfo);
+createAttrs(avatarMorfo);
 registerContract(avatarMorfo);
 
 type CrossOrigin = HTMLImgAttributes['crossorigin'];
@@ -16,13 +18,13 @@ type ReferrerPolicy = HTMLImgAttributes['referrerpolicy'];
 
 // ── Root provider ──────────────────────────────────────────────────────────
 
-interface AvatarOpts
-	extends WithRefOpts,
-		StateProps<{ status: AvatarLoadingStatus }>,
-		ActiveProps<{
-			delayMs: number;
-			onStatusChange: OnChangeFn<AvatarLoadingStatus> | undefined;
-		}> {}
+/**
+ * `status` is internal state owned by the wrapper (not part of AvatarProps),
+ * so it's intersected manually rather than derived from Props.
+ */
+type AvatarOpts = OptsFromProps<AvatarProps, 'delayMs' | 'onStatusChange', never> & {
+	status: State<AvatarLoadingStatus>;
+};
 
 export class AvatarProvider extends Provider<AvatarOpts> {
 	static readonly ctx = context<AvatarProvider>('Avatar');
@@ -37,8 +39,19 @@ export class AvatarProvider extends Provider<AvatarOpts> {
 		return new AvatarProvider(opts);
 	}
 
+	readonly runtime: MorfoRuntime;
+
 	private constructor(opts: AvatarOpts) {
-		super(opts, 'Avatar', 'provider', attrs.provider, AvatarProvider.ctx);
+		super(opts, { morfo: avatarMorfo, part: 'provider' }, AvatarProvider.ctx);
+
+		const soma = Soma.require();
+		this.runtime = createMorfoRuntime(avatarMorfo, {
+			dom: soma.dom,
+			props: {
+				status: () => opts.status.current
+			}
+		});
+		this.runtime.registerPart('provider', { id: opts.id, ref: opts.ref });
 
 		// Fire onStatusChange whenever status transitions.
 		let previous = opts.status.current;
@@ -103,21 +116,18 @@ export class AvatarProvider extends Provider<AvatarOpts> {
 
 	readonly props = $derived.by(() =>
 		this.assertProps({
-			...this.baseProps,
-			'data-status': this.opts.status.current
+			...this.runtime.partProps('provider')
 		} as const)
 	);
 }
 
 // ── Image ──────────────────────────────────────────────────────────────────
 
-interface AvatarImageOpts
-	extends WithRefOpts,
-		ActiveProps<{
-			src: string | null | undefined;
-			crossOrigin: CrossOrigin;
-			referrerPolicy: ReferrerPolicy;
-		}> {}
+type AvatarImageOpts = OptsFromProps<
+	AvatarImageProps,
+	'src' | 'crossorigin' | 'referrerpolicy',
+	never
+>;
 
 export class AvatarImageProvider extends Provider<AvatarImageOpts> {
 	static create(opts: AvatarImageOpts) {
@@ -127,16 +137,17 @@ export class AvatarImageProvider extends Provider<AvatarImageOpts> {
 	readonly provider: AvatarProvider;
 
 	private constructor(opts: AvatarImageOpts) {
-		super(opts, 'Avatar', 'image', attrs.image);
+		super(opts, { morfo: avatarMorfo, part: 'image' });
 		this.provider = AvatarProvider.require();
+		this.provider.runtime.registerPart('image', { id: opts.id, ref: opts.ref });
 
 		// Preload on src change. `watch.pre` runs synchronously so the
 		// status flips to 'loading' before the first paint.
 		watch.pre(
 			[
 				() => this.opts.src.current,
-				() => this.opts.crossOrigin.current,
-				() => this.opts.referrerPolicy.current
+				() => this.opts.crossorigin.current,
+				() => this.opts.referrerpolicy.current
 			],
 			([src, crossOrigin, referrerPolicy]) => {
 				if (!src) {
@@ -151,16 +162,15 @@ export class AvatarImageProvider extends Provider<AvatarImageOpts> {
 	readonly props = $derived.by(() => {
 		const status = this.provider.opts.status.current;
 		return this.assertProps({
-			...this.baseProps,
+			...this.provider.runtime.partProps('image'),
 			// The img element exists in DOM for all states, but is hidden
 			// until `loaded` so preloading doesn't flicker.
 			style: {
 				display: status === 'loaded' ? 'block' : 'none'
 			},
 			src: this.opts.src.current || undefined,
-			crossorigin: this.opts.crossOrigin.current,
-			referrerpolicy: this.opts.referrerPolicy.current,
-			'data-status': status
+			crossorigin: this.opts.crossorigin.current,
+			referrerpolicy: this.opts.referrerpolicy.current
 		} as const);
 	});
 }
@@ -177,17 +187,19 @@ export class AvatarFallbackProvider extends Provider<AvatarFallbackOpts> {
 	readonly provider: AvatarProvider;
 
 	private constructor(opts: AvatarFallbackOpts) {
-		super(opts, 'Avatar', 'fallback', attrs.fallback);
+		super(opts, { morfo: avatarMorfo, part: 'fallback' });
 		this.provider = AvatarProvider.require();
+		this.provider.runtime.registerPart('fallback', { id: opts.id, ref: opts.ref });
 	}
 
 	readonly props = $derived.by(() => {
 		const status = this.provider.opts.status.current;
 		// Visible while idle / loading / error. Hidden once image loaded.
 		return this.assertProps({
-			...this.baseProps,
-			style: status === 'loaded' ? { display: 'none' } : undefined,
-			'data-status': status
+			...this.provider.runtime.partProps('fallback'),
+			style: status === 'loaded' ? { display: 'none' } : undefined
 		} as const);
 	});
 }
+
+export type { OnChangeFn };

src/uix/soma/components/avatar/components/avatar-fallback.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-	import { readableActive, writableActive } from '../../../reactive';
+	import { bindProps } from '../../../reactive';
 	import { mergeProps } from '../../../props';
 	import { createId } from '../../../id';
 	import { AvatarFallbackProvider } from '../avatar-provider.svelte';
@@ -15,13 +15,12 @@
 		...restProps
 	}: AvatarFallbackProps = $props();
 
-	const state = AvatarFallbackProvider.create({
-		id: readableActive(() => id),
-		ref: writableActive(
-			() => ref,
-			(v) => (ref = v)
-		)
-	});
+	const state = AvatarFallbackProvider.create(
+		bindProps({
+			id: () => id,
+			ref: { get: () => ref, set: (v) => (ref = v) }
+		}) as unknown as Parameters<typeof AvatarFallbackProvider.create>[0]
+	);
 
 	const mergedProps = $derived(mergeProps(restProps, state.props));
 </script>

src/uix/soma/components/avatar/components/avatar-image.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-	import { readableActive, writableActive } from '../../../reactive';
+	import { bindProps } from '../../../reactive';
 	import { mergeProps } from '../../../props';
 	import { createId } from '../../../id';
 	import { AvatarImageProvider } from '../avatar-provider.svelte';
@@ -16,16 +16,15 @@
 		...restProps
 	}: AvatarImageProps = $props();
 
-	const state = AvatarImageProvider.create({
-		id: readableActive(() => id),
-		ref: writableActive(
-			() => ref,
-			(v) => (ref = v)
-		),
-		src: readableActive(() => src),
-		crossOrigin: readableActive(() => crossorigin),
-		referrerPolicy: readableActive(() => referrerpolicy)
-	});
+	const state = AvatarImageProvider.create(
+		bindProps({
+			id: () => id,
+			ref: { get: () => ref, set: (v) => (ref = v) },
+			src: () => src,
+			crossorigin: () => crossorigin,
+			referrerpolicy: () => referrerpolicy
+		}) as Parameters<typeof AvatarImageProvider.create>[0]
+	);
 
 	const mergedProps = $derived(mergeProps({}, restProps, state.props));
 </script>

src/uix/soma/components/avatar/components/avatar.svelte

@@ -1,5 +1,5 @@
 <script lang="ts">
-	import { readableActive, writableActive } from '../../../reactive';
+	import { bindProps, state } from '../../../reactive';
 	import { mergeProps } from '../../../props';
 	import { createId } from '../../../id';
 	import { AvatarProvider } from '../avatar-provider.svelte';
@@ -17,21 +17,19 @@
 		...restProps
 	}: AvatarProps = $props();
 
-	let status = $state<AvatarLoadingStatus>('idle');
+	// `status` is internal (not a public prop). Keep it as a State box so the
+	// provider can mutate it from `loadImage` and the runtime can subscribe.
+	const status = state<AvatarLoadingStatus>('idle');
 
 	const provider = AvatarProvider.create({
-		id: readableActive(() => id),
-		ref: writableActive(
-			() => ref,
-			(v) => (ref = v)
-		),
-		status: writableActive(
-			() => status,
-			(v) => (status = v)
-		),
-		delayMs: readableActive(() => delayMs),
-		onStatusChange: readableActive(() => onStatusChange)
-	});
+		...bindProps({
+			id: () => id,
+			ref: { get: () => ref, set: (v) => (ref = v) },
+			delayMs: () => delayMs,
+			onStatusChange: () => onStatusChange
+		}),
+		status
+	} as Parameters<typeof AvatarProvider.create>[0]);
 
 	const mergedProps = $derived(mergeProps(restProps, provider.props));
 </script>