Add catalog search on timeline header and fix Back to Timeline navigation.

Public GET /api/search over artists, movements, and paintings with a debounced header bar on the timeline; Back to Timeline resets zoom and gallery session.

Co-authored-by: Cursor <cursoragent@cursor.com>

client/src/api/client.ts

@@ -7,6 +7,7 @@ import type {
   MovementGalleryDetail,
   PaintingDetail,
   ArtistNavigation,
+  CatalogSearchResponse,
 } from '../types';
 
 const API = '/api';
@@ -299,6 +300,13 @@ export const api = {
   getTimeline: (start: number, end: number) =>
     fetchJson<TimelineData>(`${API}/timeline?start=${start}&end=${end}`),
 
+  search: (q: string, options?: { limit?: number; types?: string }) => {
+    const params = new URLSearchParams({ q });
+    if (options?.limit != null) params.set('limit', String(options.limit));
+    if (options?.types) params.set('types', options.types);
+    return fetchJson<CatalogSearchResponse>(`${API}/search?${params}`);
+  },
+
   getArtists: (start?: number, end?: number, movementId?: number) => {
     const params = new URLSearchParams();
     if (start != null) params.set('start', String(start));