fix(tui): recover from terminal forms - #44516

What

Recover the normal TUI composer when a cached form has already disappeared or been settled elsewhere. Replying or cancelling a stale form now treats both FormNotFoundError and FormAlreadySettledError as terminal outcomes and removes the matching form from the local projection immediately.

This supersedes #44507 with the review findings addressed.

Before / After

Before: If the TUI missed a form settlement event, the stale prompt remained active. A reply or cancellation returned 404 or 409, displayed an error, and continued blocking the normal composer. The previous fix hid the component while waiting for a list refresh, which could leave a blank blocked footer when refresh failed.

After: Form settlement lives in the client data layer. Successful, missing, and already-settled outcomes remove the matching projected form synchronously, so the keyed form component unmounts and normal keymap/composer cleanup runs immediately. Revalidation is advisory; a failed refresh cannot re-block the composer.

How

• packages/client/src/solid/data.ts adds projection-aware form reply and cancel operations, preserving global-form location headers and accepting 404/409 as terminal only when the error identifies the submitted form.
• packages/tui/src/routes/session/form.tsx delegates settlement to the data layer instead of coordinating API errors and cache state itself.
• packages/plugin/src/tui/context.ts exposes the domain-level form operations to TUI data consumers.
• packages/tui/test/cli/tui/form.test.tsx covers reply and cancellation recovery for 404 and 409, plus failed background revalidation.

Scope

This does not change form protocol or server behavior. Duplicate in-flight form submissions remain outside this stale-projection recovery fix.

Testing

• bun run test test/cli/tui/form.test.tsx from packages/tui (25 passed)
• bun run test test/solid-data.test.ts from packages/client (3 passed)
• bun typecheck from packages/tui, packages/client, and packages/plugin
• Push hook: repository-wide Turbo typecheck (32 packages passed)
• bun run lint (0 errors; pre-existing warnings remain)

Flow

sequenceDiagram
  participant TUI as FormPrompt
  participant Data as Client data
  participant API as Form API

  TUI->>Data: reply or cancel
  Data->>API: settle form
  API-->>Data: success, 404, or 409
  Data->>Data: remove matching projected form
  Data-->>TUI: terminal completion
  Note over TUI: Form unmounts; composer resumes
  Data->>API: revalidate forms in background