schema: add Idea + IdeaLog models, extend ClaudeJob/Question for ideas (M12 T-491)

- new enums IdeaStatus, ClaudeJobKind, IdeaLogType
- new models Idea (with @@unique([user_id, code]) + pbi_id @unique) and IdeaLog
- User.idea_code_counter Int @default(0) for IDEA-{nnn} code generation
- ClaudeJob.task_id nullable; new idea_id + kind fields + index
- ClaudeQuestion.story_id nullable; new idea_id field + index
- existing call sites narrowed to story-questions / task-jobs (idea-paths come in T-502+)
- includes the M12 plan doc copied from /Users/janpetervisser/.claude/plans

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

components/notifications/notifications-bridge.tsx

@@ -28,6 +28,7 @@ export async function NotificationsBridge({ userId }: NotificationsBridgeProps)
             status: 'open',
             expires_at: { gt: new Date() },
             product_id: { in: productIds },
+            story_id: { not: null },
           },
           orderBy: { created_at: 'desc' },
           take: 100,
@@ -44,19 +45,22 @@ export async function NotificationsBridge({ userId }: NotificationsBridgeProps)
           },
         })
 
-  const initial: NotificationQuestion[] = openQuestions.map((q) => ({
-    id: q.id,
-    product_id: q.product_id,
-    story_id: q.story_id,
-    task_id: q.task_id,
-    story_code: q.story.code,
-    story_title: q.story.title,
-    assignee_id: q.story.assignee_id,
-    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[] = openQuestions.flatMap((q) => {
+    if (!q.story || q.story_id === null) return []
+    return [{
+      id: q.id,
+      product_id: q.product_id,
+      story_id: q.story_id,
+      task_id: q.task_id,
+      story_code: q.story.code,
+      story_title: q.story.title,
+      assignee_id: q.story.assignee_id,
+      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(),
+    }]
+  })
 
   return <NotificationsRealtimeMount initial={initial} />
 }