- Fixed /api/stream/requests endpoint HTTP/2 INTERNAL_ERROR
- Use reply.raw.writeHead() instead of Fastify headers API for SSE
- Added 30s heartbeat to keep connection alive
- Proper event format with 'event:' and 'data:' fields
- Comprehensive error handling and cleanup on disconnect
- Mirrors working pattern from /api/stream/costs endpoint
- Resolves dashboard perpetual 'Loading...' state