realtime: idea-store + extend notifications hook for idea events (M12 T-503)

stores/idea-store.ts (Zustand):
- jobByIdea, ideaStatuses, openQuestionsByIdea
- handleIdeaJobEvent: derives optimistic ideaStatus (queued/claimed/running →
  grilling/planning; failed → grill_failed/plan_failed; done = no-op since
  the server-side update_idea_*_md is source-of-truth)
- handleIdeaQuestionEvent: list-based, removes on non-open
- setIdeaStatus / setJobStatus / clearForIdea optimistic helpers
- connectedWorkers NOT duplicated — UI reads useSoloStore(s.connectedWorkers)

lib/realtime/use-notifications-realtime.ts:
- Single SSE serves both bell-questions and idea-state. Adds dispatcher
  branches: idea-job payloads → idea-store; idea-question payloads (idea_id
  set) → idea-store; story-questions → existing notifications-store path.

Tests: 7/7 idea-store cases (queued→grilling, failed→*_failed, done no-op,
question-list management, clearForIdea isolation).
Full suite: 546/546 green.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

lib/realtime/use-notifications-realtime.ts

@@ -12,21 +12,52 @@
 
 import { useEffect, useRef } from 'react'
 import { useNotificationsStore, type NotificationQuestion } from '@/stores/notifications-store'
+import { useIdeaStore } from '@/stores/idea-store'
 
 const BACKOFF_START_MS = 1_000
 const BACKOFF_MAX_MS = 30_000
 
-interface NotifyPayload {
+// Question-payloads (M11 + M12). story_id en idea_id zijn mutually exclusive
+// (DB-check-constraint). Voor story-questions blijft het pad onveranderd;
+// idea-questions worden naar de idea-store doorgezet.
+interface QuestionPayload {
   op: 'I' | 'U'
   entity: 'question'
   id: string
   product_id: string
-  story_id: string
+  story_id: string | null
   task_id: string | null
+  idea_id?: string | null
   assignee_id: string | null
   status: 'open' | 'answered' | 'cancelled' | 'expired'
 }
 
+// Idea-job-payloads (M12). Komen uit actions/ideas.ts pg_notify.
+interface IdeaJobPayload {
+  type: 'claude_job_enqueued' | 'claude_job_status'
+  job_id: string
+  idea_id: string
+  user_id: string
+  product_id?: string | null
+  kind: 'IDEA_GRILL' | 'IDEA_MAKE_PLAN'
+  status: string
+  error?: string
+}
+
+type AnyPayload = QuestionPayload | IdeaJobPayload
+
+function isQuestionPayload(p: AnyPayload): p is QuestionPayload {
+  return 'entity' in p && p.entity === 'question'
+}
+
+function isIdeaJobPayload(p: AnyPayload): p is IdeaJobPayload {
+  return (
+    'type' in p &&
+    (p.type === 'claude_job_enqueued' || p.type === 'claude_job_status') &&
+    (p.kind === 'IDEA_GRILL' || p.kind === 'IDEA_MAKE_PLAN')
+  )
+}
+
 interface StateEvent {
   questions: NotificationQuestion[]
 }
@@ -73,11 +104,44 @@ export function useNotificationsRealtime() {
 
       source.addEventListener('message', (ev) => {
         try {
-          const payload = JSON.parse(ev.data) as NotifyPayload
-          if (payload.entity !== 'question') return
-          // Bij open of nieuwe insert → upsert (server stuurt geen vraag-tekst
-          // mee in de payload, dus we doen een mini-fetch via de same SSE's
-          // initial-state on reconnect; hier voor MVP alleen status-handling).
+          const payload = JSON.parse(ev.data) as AnyPayload
+
+          // M12 — idea-job events naar idea-store dispatchen.
+          if (isIdeaJobPayload(payload)) {
+            useIdeaStore.getState().handleIdeaJobEvent({
+              type: payload.type,
+              job_id: payload.job_id,
+              idea_id: payload.idea_id,
+              user_id: payload.user_id,
+              product_id: payload.product_id ?? null,
+              kind: payload.kind,
+              // The store-types narrow this; cast is safe because the server
+              // emits valid statuses.
+              status: payload.status as 'queued',
+              error: payload.error,
+            })
+            return
+          }
+
+          if (!isQuestionPayload(payload)) return
+
+          // M12 — idea-question events naar idea-store dispatchen.
+          if (payload.idea_id) {
+            useIdeaStore.getState().handleIdeaQuestionEvent({
+              op: payload.op,
+              entity: 'question',
+              id: payload.id,
+              product_id: payload.product_id,
+              story_id: null,
+              idea_id: payload.idea_id,
+              task_id: payload.task_id,
+              assignee_id: payload.assignee_id,
+              status: payload.status,
+            })
+            return
+          }
+
+          // Story-questions: bestaande bell-pad onveranderd.
           if (payload.status === 'open') {
             // Inkomende open vraag: we hebben de details nog niet — beste optie is
             // herfetchen door opnieuw te verbinden, of via een API. Voor v1