Feat/integration/ag UI - #40

What does this PR do?

Adds the AG-UI protocol adapter (@mobile-reality/mdma-agui) and the runtime/renderer support needed to make MDMA documents fully interactive over an AG-UI agent, plus a backend-driven hydration path so re-opened conversations render pre-populated.

Highlights:

• AG-UI bridge — streams MDMA documents from an AG-UI agent (reparsing in place so in-flight form edits/focus survive) and routes every user decision back into the agent run: form submit, button, tasklist completion, approve/deny, and webhook trigger. Ships a headless core (createMdmaAgentBridge) plus a React layer (useMdmaAgentStream, MdmaAgentView). AG-UI coupling is isolated to a minimal structural agent interface.
• initialState hydration — new option on createDocumentStore to seed component values at store creation (e.g. restoring a persisted conversation fetched from a backend). Keyed by component id → its values map (symmetric with getState()), it overlays AST defaults without emitting audit events or marking fields touched, and applies only to freshly-created components so a streaming re-parse never clobbers in-flight edits. Threaded through parseMdma, the bridge, and MdmaAgentView.
• Renderer support — tasklist now emits ACTION_TRIGGERED (its onComplete action) on the transition into all-items-checked; webhook renders a trigger button emitting INTEGRATION_CALLED.
• Dead-code cleanup — removed the never-invoked onAction methods from the core attachable handlers (renderers dispatch store actions directly; the methods were unreachable).
• Docs — new AG-UI integration page + a "Restoring State" section in the demo docs with an interactive conversation preview (fetch → 2s → form hydrates); root README corrections to the validator rules table, auto-fix pipeline, and form examples.

Type of Change

• Bug fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing behavior to change)
• Refactor (no functional change)
• Documentation
• CI / tooling

Packages Affected

• @mobile-reality/mdma-spec
• @mobile-reality/mdma-parser
• @mobile-reality/mdma-runtime
• @mobile-reality/mdma-attachables-core
• @mobile-reality/mdma-renderer-react
• @mobile-reality/mdma-prompt-pack

Checklist

• I have read the CONTRIBUTING guide.
• My code follows the existing code style (pnpm format and pnpm lint pass).
• I have added or updated tests that cover my changes.
• All tests pass (pnpm test).
• Type-checking passes (pnpm typecheck).
• I have added a changeset (pnpm changeset) if this change affects published packages.
• New or changed MDMA schemas are backwards-compatible (or marked as breaking).
• Sensitive fields are marked with sensitive: true where appropriate.

How to Test

1. pnpm install && pnpm build
2. Unit tests — pnpm --filter @mobile-reality/mdma-runtime --filter @mobile-reality/mdma-agui --filter @mobile-reality/mdma-renderer-react --filter @mobile-reality/mdma-attachables-core test (all green). Covers initialState hydration (values seeded, bindings resolve, no forged audit events, survives updateAst) and bridge routing of tasklist completion / webhook INTEGRATION_CALLED.
3. Hydration demo — pnpm --filter @mobile-reality/mdma-demo dev, open Docs → Usage → "Restoring State" → "Show live example →". In the right panel, click "Fetch saved state"; after ~2s the intake form in the agent message re-hydrates from the mock backend snapshot.
4. AG-UI end-to-end — point <MdmaAgentView agent={httpAgent} /> at an AG-UI agent that streams MDMA. Confirm: form submit / button / completing a tasklist / approve-deny / firing a webhook each resume the agent run; and passing initialState={…} renders a re-opened conversation pre-populated.

Screenshots / Examples

Restore a persisted conversation with a backend snapshot:

// Persist — snapshot each component's values
const snapshot = Object.fromEntries(
  [...store.getState().components].map(([id, c]) => [id, c.values]),
); // → { 'intake-form': { 'patient-name': 'Jane Doe' }, 'approve-1': { status: 'approved' } }

// Restore — seed a fresh store on reload
const store = createDocumentStore(ast, { initialState: snapshot });
// or via the adapter:
<MdmaAgentView agent={agent} initialState={snapshot} />