refactor: replace useQuery with useAuthQuery for improved authentication handling

- Updated multiple components to utilize useAuthQuery instead of useQuery for fetching user-related data, enhancing authentication management.
- Adjusted balance and subscription queries across various components including InitUser, ManageSubscription, PricingCards, CreditDisplay, and others to ensure consistent authentication checks.
- Improved overall code maintainability by centralizing authentication logic in the new hook.

hooks/use-auth-query.ts

@@ -0,0 +1,24 @@
+"use client";
+
+import { useConvexAuth, useQuery } from "convex/react";
+import type { FunctionReference, FunctionArgs, FunctionReturnType } from "convex/server";
+
+/**
+ * Wrapper um `useQuery` der automatisch `"skip"` nutzt wenn der
+ * Convex-Auth-Token noch nicht bereit ist. Verhindert "Unauthenticated"-Fehler
+ * bei Queries die `requireAuth` nutzen.
+ *
+ * Nutzt nur `isAuthenticated` (nicht `isLoading`) als Guard — wenn ein
+ * `initialToken` vom SSR vorhanden ist, springt `isAuthenticated` sofort
+ * auf `true` ohne Loading-Phase, sodass Queries ohne Verzögerung feuern.
+ */
+export function useAuthQuery<F extends FunctionReference<"query">>(
+  query: F,
+  ...args: [] | [FunctionArgs<F> | "skip"]
+): FunctionReturnType<F> | undefined {
+  const { isAuthenticated } = useConvexAuth();
+
+  const shouldSkip = !isAuthenticated || args[0] === "skip";
+
+  return useQuery(query, shouldSkip ? "skip" : (args[0] ?? ({} as FunctionArgs<F>)));
+}