fix(m12): user can answer idea-questions — inline + bell support

Two gaps discovered during the first live grill-session of IDEA-002:
the agent posted a question, but the user had no UI to answer it.
1. Idea-questions only appeared on the Timeline-tab as read-only entries
2. Notifications-bell fetched + handled story-questions only

This fix:

**Inline answer-form in IdeaTimeline** (components/ideas/idea-timeline.tsx)
- Open questions now render an AnswerForm directly under the question text
- Multi-choice options become clickable buttons (one-click submit); free-text
  fallback via collapsed details/textarea
- Plain free-text questions render textarea + Verzend
- Calls existing answerQuestion server-action; toast + router.refresh on success

**Notifications-bell extended for idea-questions**
- stores/notifications-store.ts: NotificationQuestion → discriminated union
  (kind: 'story' | 'idea'); forYouCount treats idea-questions as always-for-you
  (idea is strictly user_id-only — only the owner sees them)
- components/notifications/notifications-bridge.tsx: parallel fetch of
  story-questions (productAccessFilter) + idea-questions (idea.user_id ===
  session.userId); merged + sorted by created_at
- components/notifications/notifications-sheet.tsx: renders idea_code/title
  for kind='idea'
- components/notifications/answer-modal.tsx: header + open-link branch on
  kind (idea → /ideas/[id]?tab=timeline; story → existing /sprint link)
- lib/realtime/use-notifications-realtime.ts: idea-question events also
  trigger close+reconnect on 'open' (loads fresh detail) and remove(id) on
  non-open — same pattern story-questions already use
- components/shared/notifications-bell.tsx: badge counts idea-questions as
  for-you regardless of assignee

**Security gap closed (actions/questions.ts answerQuestion)**
Before: accepted any answer if user has product-access.
After: idea-questions require idea.user_id === session.userId; story-
questions keep the existing productAccessFilter path. (Prisma 7 rejects
\`{ not: null }\` in WHERE; routing happens app-level after a single fetch.)

Tests: 546/546 still green.

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

components/notifications/answer-modal.tsx

@@ -87,20 +87,26 @@ export function AnswerModal({ question, isDemo, onClose }: AnswerModalProps) {
             <div className="flex flex-col gap-1">
               <DialogTitle className="text-xl font-semibold">Beantwoord Claude</DialogTitle>
               <DialogDescription>
-                <span className="font-mono">{question.story_code ?? 'story'}</span>
+                <span className="font-mono">
+                  {question.kind === 'idea' ? question.idea_code : (question.story_code ?? 'story')}
+                </span>
                 {' — '}
-                {question.story_title}
+                {question.kind === 'idea' ? question.idea_title : question.story_title}
               </DialogDescription>
             </div>
           </div>
 
           <div className="flex-1 overflow-y-auto px-6 py-6 space-y-6">
             <Link
-              href={`/products/${question.product_id}/sprint`}
+              href={
+                question.kind === 'idea'
+                  ? `/ideas/${question.idea_id}?tab=timeline`
+                  : `/products/${question.product_id}/sprint`
+              }
               className="text-primary inline-flex items-center gap-1 self-start text-xs hover:underline"
             >
               <ExternalLink className="h-3.5 w-3.5" />
-              <span>Open in Sprint</span>
+              <span>{question.kind === 'idea' ? 'Open idee' : 'Open in Sprint'}</span>
             </Link>
 
             <div className="bg-surface-container-low rounded-md border p-3 text-sm whitespace-pre-wrap">

components/notifications/notifications-bridge.tsx

@@ -48,9 +48,10 @@ export async function NotificationsBridge({ userId }: NotificationsBridgeProps)
           },
         })
 
-  const initial: NotificationQuestion[] = openQuestions.flatMap((q) => {
+  const storyQuestions: NotificationQuestion[] = openQuestions.flatMap((q) => {
     if (!q.story || q.story_id === null) return []
     return [{
+      kind: 'story' as const,
       id: q.id,
       product_id: q.product_id,
       story_id: q.story_id,
@@ -65,5 +66,45 @@ export async function NotificationsBridge({ userId }: NotificationsBridgeProps)
     }]
   })
 
+  // M12 hotfix: idea-questions ook in de bel. user_id-only scope (idee is privé).
+  const ideaOpenQuestions = await prisma.claudeQuestion.findMany({
+    where: {
+      status: 'open',
+      expires_at: { gt: new Date() },
+      idea: { user_id: userId },
+    },
+    orderBy: { created_at: 'desc' },
+    take: 100,
+    select: {
+      id: true,
+      product_id: true,
+      idea_id: true,
+      question: true,
+      options: true,
+      created_at: true,
+      expires_at: true,
+      idea: { select: { id: true, code: true, title: true } },
+    },
+  })
+
+  const ideaQuestions: NotificationQuestion[] = ideaOpenQuestions.flatMap((q) => {
+    if (!q.idea || q.idea_id === null) return []
+    return [{
+      kind: 'idea' as const,
+      id: q.id,
+      product_id: q.product_id,
+      idea_id: q.idea_id,
+      idea_code: q.idea.code,
+      idea_title: q.idea.title,
+      question: q.question,
+      options: Array.isArray(q.options) ? (q.options as string[]) : null,
+      created_at: q.created_at.toISOString(),
+      expires_at: q.expires_at.toISOString(),
+    }]
+  })
+
+  const initial: NotificationQuestion[] = [...storyQuestions, ...ideaQuestions]
+    .sort((a, b) => (a.created_at < b.created_at ? 1 : -1))
+
   return <NotificationsRealtimeMount initial={initial} />
 }

components/notifications/notifications-sheet.tsx

@@ -54,7 +54,12 @@ export function NotificationsSheet({
           ) : (
             <ul className="mt-4 flex flex-col gap-2 px-4 pb-4">
               {questions.map((q) => {
-                const forYou = q.assignee_id === currentUserId
+                // story-questions: forYou wanneer assignee = ingelogd; idee-vragen
+                // zijn altijd "voor jou" (idee is strikt user_id-only).
+                const forYou =
+                  q.kind === 'idea' || q.assignee_id === currentUserId
+                const code = q.kind === 'idea' ? q.idea_code : (q.story_code ?? '—')
+                const title = q.kind === 'idea' ? q.idea_title : q.story_title
                 return (
                   <li key={q.id}>
                     <button
@@ -67,12 +72,8 @@ export function NotificationsSheet({
                       )}
                     >
                       <div className="flex items-baseline gap-2">
-                        <span className="font-mono text-xs opacity-80">
-                          {q.story_code ?? '—'}
-                        </span>
-                        <span className="line-clamp-1 text-sm font-medium">
-                          {q.story_title}
-                        </span>
+                        <span className="font-mono text-xs opacity-80">{code}</span>
+                        <span className="line-clamp-1 text-sm font-medium">{title}</span>
                       </div>
                       <p
                         className={cn(