feat: Notifications page, Sidebar layout fixes, and Achievements enhancements

- implemented /notifications page with overdue/upcoming alerts
- Fixed sidebar scrolling in collapsed mode
- Moved notification button to sidebar footer
- Enhanced Achievements page with streak stats and tooltips
- Improved XP history to show task titles
- Added missing translations (en/de)
- Removed top bar header
- Fixed Docker environment routing

client/src/lib/queryClient.ts

@@ -28,23 +28,23 @@ export const getQueryFn: <T>(options: {
   on401: UnauthorizedBehavior;
 }) => QueryFunction<T> =
   ({ on401: unauthorizedBehavior }) =>
-  async ({ queryKey }) => {
-    const res = await fetch(queryKey.join("/") as string, {
-      credentials: "include",
-    });
+    async ({ queryKey }) => {
+      const res = await fetch(queryKey.join("/") as string, {
+        credentials: "include",
+      });
 
-    if (unauthorizedBehavior === "returnNull" && res.status === 401) {
-      return null;
-    }
+      if (unauthorizedBehavior === "returnNull" && res.status === 401) {
+        return null;
+      }
 
-    await throwIfResNotOk(res);
-    return await res.json();
-  };
+      await throwIfResNotOk(res);
+      return await res.json();
+    };
 
 export const queryClient = new QueryClient({
   defaultOptions: {
     queries: {
-      queryFn: getQueryFn({ on401: "throw" }),
+      queryFn: getQueryFn({ on401: "returnNull" }),
       refetchInterval: false,
       refetchOnWindowFocus: false,
       staleTime: Infinity,