chore(build): refactor codebase for production

src/pages/student/Rewards.tsx

@@ -434,9 +434,10 @@ export const Rewards = () => {
       if (!user) return;
       const authStorage = localStorage.getItem("auth-storage");
       if (!authStorage) return;
-      const {
-        state: { token },
-      } = JSON.parse(authStorage) as { state?: { token?: string } };
+      const parsed = JSON.parse(authStorage) as {
+        state?: { token?: string };
+      } | null;
+      const token = parsed?.state?.token;
       if (!token) return;
       try {
         setLoading(true);
@@ -481,7 +482,7 @@ export const Rewards = () => {
 
   // ✅ FIX 2: Safely cast user_rank — null becomes undefined so all optional chaining works
   const ur = (leaderboard?.user_rank ?? undefined) as
-    | Record<string, unknown>
+    | Record<string, number>
     | undefined;
 
   const islandStats = getIslandStats(ur, activeTab);