feat: Introduce data manager service with PocketBase authentication and professor dashboard.

frontend/src/view/professor/ProfessorDashboard.vue

@@ -68,6 +68,7 @@ onMounted(async () => {
       return (b.confidenceScore || 0) - (a.confidenceScore || 0); // Descending order
     });
     
+    // Clear temporary entries and set actual modules
     modules.value = sortedModules;
     
     // Pre-select modules with confidence score >= 0.7 (good match or better)
@@ -77,12 +78,15 @@ onMounted(async () => {
   } catch (error: unknown) {
     console.error("Failed to fetch modules", error);
     const err = error as { status?: number; message?: string };
+    // Clear temporary entries on error
+    modules.value = [];
     // If unauthorized, redirect to home
     if (err.status === 401 || err.message?.includes("401")) {
       pb.authStore.clear();
       router.push("/");
     }
   } finally {
+    // Always disable loading animation
     loading.value = false;
   }
 });