fix: use host.docker.internal for Transmission RPC connection

dashboard/backend/routers/transmission.py

@@ -10,17 +10,15 @@ router = APIRouter(prefix="/api/transmission", tags=["transmission"])
 def get_session_id() -> str:
     """Get Transmission RPC session ID"""
     try:
-        result = subprocess.run(
-            ["ssh", "nas", "curl -si -u 'admin:admin' 'http://127.0.0.1:9091/transmission/rpc' 2>&1 | grep -i 'X-Transmission-Session-Id:' | cut -d' ' -f2 | tr -d '\\r'"],
-            capture_output=True,
-            text=True,
-            shell=True,
-            timeout=5
-        )
-        session_id = result.stdout.strip()
-        if not session_id:
-            raise Exception("Failed to get session ID")
-        return session_id
+        with httpx.Client(timeout=5.0) as client:
+            response = client.get(
+                "http://host.docker.internal:9091/transmission/rpc",
+                auth=("admin", "admin")
+            )
+            session_id = response.headers.get("X-Transmission-Session-Id")
+            if not session_id:
+                raise Exception("Failed to get session ID from headers")
+            return session_id
     except Exception as e:
         raise HTTPException(status_code=500, detail=f"Failed to get Transmission session ID: {str(e)}")
 
@@ -37,7 +35,7 @@ def transmission_rpc(method: str, arguments: Dict[str, Any] = None) -> Dict[str,
         # Use httpx to make the request
         with httpx.Client(timeout=10.0) as client:
             response = client.post(
-                "http://100.78.131.124:9091/transmission/rpc",
+                "http://host.docker.internal:9091/transmission/rpc",
                 json=payload,
                 auth=("admin", "admin"),
                 headers={"X-Transmission-Session-Id": session_id}