Phase 5: Notifications — WebSocket, APScheduler, AI tool, health review

Backend:
- Notification model + Alembic migration
- Notification service: CRUD, mark read, unread count, pending scheduled
- WebSocket manager singleton for real-time push
- WebSocket endpoint /ws/notifications with JWT auth via query param
- APScheduler integration: periodic notification sender (every 60s),
  daily proactive health review job (8 AM)
- AI tool: schedule_notification (immediate or scheduled)
- Health review worker: analyzes user memory via Claude, creates
  ai_generated notifications with WebSocket push

Frontend:
- Notification API client + Zustand store
- WebSocket hook with auto-reconnect (exponential backoff)
- Notification bell in header with unread count badge + dropdown
- Notifications page with type badges, mark read, mark all read
- WebSocket initialized in AppLayout for app-wide real-time updates
- Enabled notifications nav in sidebar
- English + Russian translations

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/app/services/ai_service.py

@@ -14,6 +14,8 @@ from app.services.context_service import DEFAULT_SYSTEM_PROMPT, get_primary_cont
 from app.services.chat_service import get_chat, save_message
 from app.services.memory_service import get_critical_memories, create_memory, get_user_memories
 from app.services.document_service import search_documents
+from app.services.notification_service import create_notification
+from app.services.ws_manager import manager
 
 client = AsyncAnthropic(api_key=settings.ANTHROPIC_API_KEY)
 
@@ -68,6 +70,28 @@ AI_TOOLS = [
             "required": [],
         },
     },
+    {
+        "name": "schedule_notification",
+        "description": "Schedule a notification or reminder for the user. Can be immediate or scheduled for a future time.",
+        "input_schema": {
+            "type": "object",
+            "properties": {
+                "title": {"type": "string", "description": "Notification title"},
+                "body": {"type": "string", "description": "Notification body text"},
+                "scheduled_at": {
+                    "type": "string",
+                    "description": "ISO 8601 datetime for scheduled delivery. Omit for immediate.",
+                },
+                "type": {
+                    "type": "string",
+                    "enum": ["reminder", "alert", "info"],
+                    "description": "Notification type",
+                    "default": "reminder",
+                },
+            },
+            "required": ["title", "body"],
+        },
+    },
 ]
 
 
@@ -104,6 +128,40 @@ async def _execute_tool(
         items = [{"category": e.category, "title": e.title, "content": e.content, "importance": e.importance} for e in entries]
         return json.dumps({"entries": items, "count": len(items)})
 
+    elif tool_name == "schedule_notification":
+        from datetime import datetime
+        scheduled_at = None
+        if tool_input.get("scheduled_at"):
+            scheduled_at = datetime.fromisoformat(tool_input["scheduled_at"])
+
+        notif = await create_notification(
+            db, user_id,
+            title=tool_input["title"],
+            body=tool_input["body"],
+            type=tool_input.get("type", "reminder"),
+            scheduled_at=scheduled_at,
+        )
+        await db.commit()
+
+        # Push immediately if not scheduled
+        if not scheduled_at:
+            await manager.send_to_user(user_id, {
+                "type": "new_notification",
+                "notification": {
+                    "id": str(notif.id),
+                    "title": notif.title,
+                    "body": notif.body,
+                    "type": notif.type,
+                    "created_at": notif.created_at.isoformat(),
+                },
+            })
+
+        return json.dumps({
+            "status": "scheduled" if scheduled_at else "sent",
+            "id": str(notif.id),
+            "title": notif.title,
+        })
+
     return json.dumps({"error": f"Unknown tool: {tool_name}"})