MQTT-based live CPU/RAM metrics + remove auth from HA control

- Enrich server data with MQTT system topics (cpu_usage_percent,
  ram_usage_percent, temp, model etc.) published by Unraid MQTT Agent
- Works for both Daddelolymp and Adriahub topics
- MQTT overlay runs on every request (even cached) for fresh metrics
- Remove JWT auth from /api/ha/control — local dashboard doesn't need it
- Add cpu brand field to GraphQL query

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

server/services/unraid_service.py

@@ -17,7 +17,7 @@ _GRAPHQL_QUERY = """
   online
   info {
     os { hostname uptime }
-    cpu { model cores threads }
+    cpu { model cores threads manufacturer brand }
     memory { layout { size type } }
   }
   docker {
@@ -72,9 +72,9 @@ def _parse_graphql_response(data: Dict[str, Any], result: Dict[str, Any]) -> Non
 
     cpu_info = info.get("cpu", {})
     result["cpu"]["cores"] = cpu_info.get("cores", 0)
-    # GraphQL API doesn't expose CPU usage % — keep 0
-    # Store threads for the frontend to show
     result["cpu"]["threads"] = cpu_info.get("threads", 0)
+    result["cpu"]["brand"] = cpu_info.get("brand", "")
+    # GraphQL API doesn't expose CPU usage % — keep 0
 
     # Memory: sum layout slots for total GB
     mem_layout = info.get("memory", {}).get("layout", [])