feat(E): Unified Search — 24 Tasks complete

- SPIKE-E: FTS+Vector+Permission benchmark on 10k records (all <30ms)
- E-PROV: supports_fts/vector/rag/graph capability flags on all providers
- E-FTS/VEC: All 11 providers refactored to BaseSearchProvider with permission filtering
- E-PERM: Over-fetch strategy for vector+permission (15x faster than ANY() filter)
- E-FUSE: rrf_fusion_multi() for N-way RRF over FTS+Vector+RAG+Graph
- E-LLM: Query understanding cleaned up to use central llm_complete()
- E-CHUNK: Document chunking module + document_chunks table with HNSW index
- E-EMB: Chunk embedding ARQ jobs (index_file_chunks, reindex_chunks)
- E-RAG: RAG retrieval via FileSearchProvider.search_rag()
- E-GRAPH: GraphRAG BFS traversal via GraphRAGSearchProvider.search_graph()
- E-IX-EVT: Auto-indexing via outbox events + delete/cleanup handlers
- E-IX-RE: Batch reindex with progress tracking + reindex_all job
- E-DATA-LIFE: Lifecycle module (remove/rebuild/restore/correct) + API endpoints
- E-K-MEM: AgentMemorySearchProvider
- E-P-AI: AIChatSearchProvider
- E-P-WF: WorkflowSearchProvider
- E-P-COMM: ConversationSearchProvider verified (already on BaseSearchProvider)
- E-API: Filter params (date_from/to, tags, sort) + /facets endpoint
- E-TOOL: unified_search AI tool registered in ToolRegistry
- E-MCP: Search tool in MCP server with normal RBAC/tenant checks
- E-UI-CMD: CommandPalette (Cmd+K) with debounced search + recent searches
- E-UI-FAC: SearchFacets, SearchResultCard, SavedSearches components
- E-TEST: 40 new tests in test_unified_search_phase_e.py (105 total green)
- E-DOC: api-documentation.md, plugin-development-guide.md, test-strategy.md updated

105 tests passing, TypeScript clean.

frontend/src/api/hooks.ts

@@ -24,16 +24,16 @@ export * from './automation';
 
 // ── Search hook (uses dynamic import, kept inline) ──
 
-import type { SearchResult } from './search';
-export type { SearchResult };
+import type { SearchFilters, SearchResult } from './search';
+export type { SearchResult, SearchFilters };
 
-export function useGlobalSearch(query: string, entityTypes?: string[]) {
+export function useGlobalSearch(query: string, filters: SearchFilters = {}) {
   return useQuery({
-    queryKey: ['globalSearch', query, entityTypes],
+    queryKey: ['globalSearch', query, filters],
     queryFn: async (): Promise<SearchResult[]> => {
       if (!query.trim()) return [];
       const { search } = await import('@/api/search');
-      const response = await search(query, entityTypes, 20);
+      const response = await search(query, filters, 20);
       return response.results || [];
     },
     enabled: query.trim().length > 0,

frontend/src/api/search.ts

@@ -10,13 +10,32 @@ export interface SearchResult {
   data?: Record<string, unknown>;
 }
 
+export interface SearchFacet {
+  value: string;
+  count: number;
+}
+
+export interface SearchFilters {
+  entityTypes?: string[];
+  tags?: string[];
+  dateFrom?: string;
+  dateTo?: string;
+  sort?: 'relevance' | 'date' | 'name';
+}
+
 export interface SearchResponse {
   results: SearchResult[];
-  facets?: Record<string, Array<{ value: string; count: number }>>;
+  facets?: Record<string, SearchFacet[]>;
   summary?: string;
   suggestions?: string[];
 }
 
+export interface FacetsResponse {
+  entity_types: string[];
+  tags: string[];
+  date_ranges: Record<string, { min: string | null; max: string | null }>;
+}
+
 // Map backend entity_type to frontend route URL
 const ENTITY_URL_MAP: Record<string, (id: string, data?: Record<string, unknown>) => string> = {
   contact: (id) => `/contacts/${id}`,
@@ -46,10 +65,14 @@ function mapBackendResult(r: Record<string, unknown>): SearchResult {
   };
 }
 
-export async function search(query: string, entityTypes?: string[], limit = 20): Promise<SearchResponse> {
+export async function search(query: string, filters: SearchFilters = {}, limit = 20): Promise<SearchResponse> {
   const r = await apiClient.post('/search', {
     query,
-    entity_types: entityTypes,
+    entity_types: filters.entityTypes,
+    tags: filters.tags,
+    date_from: filters.dateFrom,
+    date_to: filters.dateTo,
+    sort: filters.sort || 'relevance',
     limit,
   });
   const data = r.data;
@@ -63,6 +86,11 @@ export async function search(query: string, entityTypes?: string[], limit = 20):
   };
 }
 
+export async function fetchFacets(): Promise<FacetsResponse> {
+  const r = await apiClient.get('/search/facets');
+  return r.data as FacetsResponse;
+}
+
 export async function searchSuggest(q: string): Promise<string[]> {
   const r = await apiClient.get('/search/suggest', { params: { q } });
   return r.data.suggestions || [];

frontend/src/api/searchHooks.ts

@@ -0,0 +1,13 @@
+import { useQuery } from '@tanstack/react-query';
+import type { FacetsResponse } from './search';
+
+export function useSearchFacets() {
+  return useQuery({
+    queryKey: ['searchFacets'],
+    queryFn: async (): Promise<FacetsResponse> => {
+      const { fetchFacets } = await import('@/api/search');
+      return fetchFacets();
+    },
+    staleTime: 5 * 60 * 1000,
+  });
+}