feat: Complete Stage 2 frontend refactor

- Removed deprecated fields from Content and Task models, including entity_type, sync_status, and cluster_role.
- Updated Content model to include new fields: content_type, content_structure, taxonomy_terms, source, external_id, and cluster_id.
- Refactored Writer module components (Content, ContentView, Dashboard, Tasks) to align with new schema.
- Enhanced Dashboard metrics and removed unused filters.
- Implemented ClusterDetail page to display cluster information and associated content.
- Updated API service interfaces to reflect changes in data structure.
- Adjusted sorting and filtering logic across various components to accommodate new field names and types.
- Improved user experience by providing loading states and error handling in data fetching.

frontend/src/App.tsx

@@ -21,6 +21,7 @@ const Home = lazy(() => import("./pages/Dashboard/Home"));
 const PlannerDashboard = lazy(() => import("./pages/Planner/Dashboard"));
 const Keywords = lazy(() => import("./pages/Planner/Keywords"));
 const Clusters = lazy(() => import("./pages/Planner/Clusters"));
+const ClusterDetail = lazy(() => import("./pages/Planner/ClusterDetail"));
 const Ideas = lazy(() => import("./pages/Planner/Ideas"));
 const KeywordOpportunities = lazy(() => import("./pages/Planner/KeywordOpportunities"));
 
@@ -191,6 +192,13 @@ export default function App() {
                 </ModuleGuard>
               </Suspense>
             } />
+            <Route path="/planner/clusters/:id" element={
+              <Suspense fallback={null}>
+                <ModuleGuard module="planner">
+                  <ClusterDetail />
+                </ModuleGuard>
+              </Suspense>
+            } />
             <Route path="/planner/ideas" element={
               <Suspense fallback={null}>
                 <ModuleGuard module="planner">