feat(election): audit log UI with server-side filter, pagination, entity-aware actions

- New ElectionAuditLogComponent: timeline view, expandable JSON details
- Server-side filtering: entityType, action, full-text search (350ms debounce)
- Pagination bar with page size selector (10/20/50 per page)
- Action dropdown filtered by selected entity (CANDIDATE shows only
  candidate actions, NOMINATION shows nomination actions, etc.)
- Entity change resets action filter automatically
- election.service.ts: getAuditLog() sends query params to backend
- Audit Log button added to every election card in dashboard
- Route: /election/:electionId/audit-log

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/app/election/election-routing.module.ts

@@ -73,6 +73,14 @@ const routes: Routes = [
           loadComponent: () =>
             import('./components/election-results/election-results.component').then((m) => m.ElectionResultsComponent),
           data: { title: 'Election Results' }
+        },
+        {
+          path: ':electionId/audit-log',
+          loadComponent: () =>
+            import('./components/election-audit-log/election-audit-log.component').then(
+              (m) => m.ElectionAuditLogComponent
+            ),
+          data: { title: 'Election Audit Log' }
         }
       ]
     }