Fix error-state handling, token refresh stale return, and modules null crash

src/lib/api/auth.ts

@@ -160,7 +160,7 @@ async function executeRefresh(refreshTokenStr: string): Promise<string | null> {
           .getState()
           .setError("Session expired. Please reconnect your wallet.");
       }
-      return useAuthStore.getState().jwt;
+      return null;
     } finally {
       inFlightRefreshPromise = null;
     }

src/lib/api/courses.ts

@@ -235,7 +235,7 @@ export async function getCourseModules(
   signal?: AbortSignal
 ): Promise<Module[]> {
   const course = await getCourse(courseId, jwt, signal);
-  return [...course.modules].sort((a, b) => a.order - b.order);
+  return [...(course.modules ?? [])].sort((a, b) => a.order - b.order);
 }
 
 /**

src/lib/hooks/use-courses.ts

@@ -178,9 +178,12 @@ export function useCourses() {
     try {
       const data = await loadEnrollments(jwt, controller.signal);
       setEnrollments(data);
+      setError(null);
     } catch (err) {
       if (isAbortError(err)) return;
-      console.error("Failed to fetch enrollments:", err);
+      setError(
+        err instanceof Error ? err.message : "Failed to fetch enrollments"
+      );
     }
   }, [jwt, setEnrollments]);
 

src/lib/hooks/use-rewards.ts

@@ -116,9 +116,11 @@ export function useRewards() {
         setHistory(cached.history);
         setClaimables(cached.claimables);
       }
+      setError(null);
     } catch (e) {
       if (isAbortError(e)) return;
       console.error("Failed to fetch rewards:", e);
+      setError(e instanceof Error ? e.message : "Failed to fetch rewards");
     } finally {
       setLoading(false);
     }