Create SSE streaming endpoint for real-time health updates

[lbedner]

Objective

Implement a Server-Sent Events (SSE) endpoint that streams real-time health and queue updates to the dashboard.

Tasks

• Add sse-starlette dependency to requirements
• Create /health/stream endpoint for SSE streaming
• Implement async generator for streaming responses
• Add connection management for multiple concurrent clients
• Handle client disconnections gracefully
• Implement heartbeat/keepalive messages

Technical Requirements

• Use FastAPI's StreamingResponse or sse-starlette's EventSourceResponse
• Support multiple concurrent SSE connections
• Implement proper error handling and connection cleanup
• Add rate limiting to prevent abuse
• Include authentication/authorization checks

Example Implementation

from sse_starlette.sse import EventSourceResponse

@router.get('/health/stream')
async def health_stream(request: Request):
    async def event_generator():
        while True:
            if await request.is_disconnected():
                break
            data = await get_health_update()
            yield {"data": json.dumps(data)}
            await asyncio.sleep(1)
    
    return EventSourceResponse(event_generator())

Dependencies

• Requires ASGI server (Uvicorn) for proper async support
• May need to adjust CORS settings for SSE