Commit B of the Toast pilot. The runtime.trigger() contract from commit A
now has its first real consumer: all three dismiss paths route through
`runtime.trigger('dismiss')`, which emits the perceptual signal one frame
before the toaster mutates state.
Multi-instance architecture validated
Toast is the first component with multiple per-instance subtrees: each
toast in the queue is its own scope with its own children. Two runtime
instances coexist per Toast tree:
ToastProvider (root)
└── runtime instance A — registers `viewport` only
ToastItemProvider (one per active toast in queue)
└── runtime instance B — registers `item` + its children
(`title`, `description`, `action`, `close`)
`partRef('item')` resolves to THIS toast's element because the lookup
happens on THIS Item's runtime, not a shared one. `runtime.trigger('dismiss')`
on Item-B targets Item-B's DOM element. Per-toast isolation by construction.
dismiss wired through runtime.trigger
Three call sites now go through the same path instead of calling
`toaster.dismiss(id)` directly:
- ToastCloseProvider.onclick (user clicks the × button)
- ToastItemProvider startTimer setTimeout callback (auto-dismiss)
- ToastItemProvider onpointerup (swipe gesture meets threshold)
The runtime fires `data-event="dismiss"` on the item, awaits one rAF for
CSS to observe it, then calls the dismiss handler that mutates
`toast.dismissing = true`. The item's effect re-derives `data-state="closed"`
from `isOpen = !dismissing` and writes it via dom.apply on the next tick.
intent-driven role / aria-live still works
The morfo's `mapRef(propRef('intent'), { neutral: 'status', risk: 'alert', … })`
for `role` and `aria-live` is resolved by the runtime per-Item: each toast
reads its own `intent` from `opts.toast.current.intent` via the per-Item
runtime sources. Risk/threat toasts get `role=alert` + `aria-live=assertive`;
the others get `role=status` + `aria-live=polite`. No code in the provider
selects this — the morfo declares it, the resolver computes it.
Per-part props
Action's `altText` is per-instance per-action — passed to the runtime via
`registerPart('action', { props: { altText: () => opts.altText.current } })`.
Validates that the runtime's per-part source override (introduced in
commit 8ede5353 but never exercised) works as designed.
Translation lookup
Close's `aria-label` resolves through `v.translationRef` against the Item
runtime's `translate` source (`soma.langs.ts`). Confirms translationRef
ergonomics through the runtime path.
What this commit does NOT do (deferred)
- `present` and `announce` events: declared in the morfo but not wired.
Would fire on Item mount; needs a small effect at the right phase.
- `runtime.keydown` for Item's `Escape` keyboard declaration: requires
the V2 runtime API.
- presence layer (data-starting-style/data-ending-style) still flows
through Svelte render — not migrated to dom.apply. Mixed model is OK
while the boundary is clearly between morfo-declared attrs (runtime)
and layer-declared transitions (Svelte).
Verification
- 84/84 focused unit tests green.
- 66/66 morfo-check (toast included).
- 68/68 smoke routes 200 OK.
- svelte-check unchanged at 155.
