feat: Live-Metriken via WebSockets (Phase 3)

routers/system.py

@@ -4,9 +4,10 @@ Greift lokal auf psutil und sysfs zu.
 """
 
 from pathlib import Path
+import asyncio
 import psutil
 
-from fastapi import APIRouter, Depends
+from fastapi import APIRouter, Depends, WebSocket, WebSocketDisconnect
 from auth import auth
 
 router = APIRouter(prefix="/api/system", dependencies=[Depends(auth)])
@@ -89,3 +90,15 @@ def system_status():
         },
         "gpu_temp": temps["gpu"]
     }
+
+@router.websocket("/stream")
+async def system_stream(websocket: WebSocket):
+    await websocket.accept()
+    try:
+        while True:
+            # Sende Live-Daten alle 500ms
+            data = system_status()
+            await websocket.send_json(data)
+            await asyncio.sleep(0.5)
+    except WebSocketDisconnect:
+        pass