fix: déconnexion Gitea effective + menu user light mode

1. _require_gitea: retrait fallback admin token → 401 si pas connecté
2. user-menu-dropdown: background var(--bg-primary) au lieu de #1E1E1E
3. applyTheme() déjà immédiat via style.setProperty sur documentElement

app/routers/gitea.py

@@ -6,11 +6,11 @@ router = APIRouter(tags=["gitea"], prefix="/api/gitea")
 
 
 def _require_gitea(request: Request):
-    """Return a per-user GiteaClient, falling back to admin token for read-only ops."""
+    """Return a per-user GiteaClient or raise 401 if not connected."""
-    from app.services.gitea_client import get_user_gitea_client, GiteaClient
+    from app.services.gitea_client import get_user_gitea_client
     client = get_user_gitea_client(request)
     if not client:
-        client = GiteaClient()  # fallback to server admin token
+        raise HTTPException(status_code=401, detail="Gitea account not linked. Go to Settings → Integrations to connect.")
     return client
 
 

static/css/app.css

@@ -214,7 +214,7 @@ input, select, textarea { font-family: inherit; color: inherit; }
   left: 8px;
   right: 8px;
   margin-top: 4px;
-  background: #1E1E1E;
+  background: var(--bg-primary);
   border: 1px solid var(--border-strong);
   border-radius: 10px;
   box-shadow: 0 12px 32px rgba(0,0,0,.6);