Real-time alert system complete implementation and fixes

[izzathnisfer]

Summary

Implements the real-time alert broadcasting pipeline and auth-protected API routes for the D2 Intelligence layer.

Changes

Real-time Alert System (Socket.IO)

• Added Socket.IO server mounted on /socket.io in app.py
• Kafka consumer (_consume_alerts) broadcasts incoming alerts to all connected clients in real-time
• Socket authentication via session token (configurable via socketio_require_auth)
• Room-based subscriptions (join_room / leave_room events)

Auth-Protected Alerts Route

• GET /api/alerts — doctors/admins see all alerts; patients see only their own
• PATCH /api/alerts/{id}/acknowledge — restricted to doctor and admin roles
• Logs acknowledgment with username and auth subject ID

Configuration

• Added session_secret_key, cors_allow_origins, socketio_require_auth, socketio_allow_origins to Settings

Observability

• New Prometheus counters: ALERTS_DELIVERED, ALERTS_DELIVERY_FAILED, ALERTS_ACKNOWLEDGED

Testing

• Unit tests: alert payload builder, auth token extraction, origin splitting, alerts route
• Integration tests: Socket.IO bridge, worker pipeline end-to-end

Scripts

• scripts/simulate_alert.py — publishes test vitals payloads to Kafka for local testing

Commits

• feat: implement real-time alert system with Socket.IO
• feat: async handling and add unit tests for auth token extraction and origin splitting
• feat: add simulate_alert script for publishing vitals payloads to Kafka