Speed up timeline load with portrait thumbs, bootstrap API, and caching.

Add catalog bootstrap endpoint, portrait thumbnail pipeline, lazy queued timeline images, gzip compression, and 3D texture throttling with code-split VirtualGallery.

client/src/api/client.ts

@@ -1,5 +1,6 @@
 import type {
   TimelineData,
+  CatalogBootstrap,
   YearBounds,
   Artist,
   ArtistDetail,
@@ -62,13 +63,25 @@ export function portraitUrl(path: string | null | undefined, revision?: number):
   return `${base}${base.includes('?') ? '&' : '?'}v=${revision}`;
 }
 
-/** Image for 3D gallery — local cached files only (API fetch is too slow for realtime 3D) */
+/** Small portrait for timeline / movement flow (~256px). Falls back to full portrait. */
+export function portraitThumbUrl(
+  artist: {
+    portrait_thumb_path?: string | null;
+    portrait_path?: string | null;
+  },
+  revision?: number
+): string {
+  const path = artist.portrait_thumb_path || artist.portrait_path;
+  return portraitUrl(path, revision);
+}
+
+/** Image for 3D gallery — prefer thumbnail for faster texture loads */
 export function galleryImageUrl(painting: {
   thumbnail_path?: string | null;
   image_path?: string | null;
 }): string | null {
-  if (painting.image_path) return `/images/${painting.image_path}`;
   if (painting.thumbnail_path) return `/images/${painting.thumbnail_path}`;
+  if (painting.image_path) return `/images/${painting.image_path}`;
   return null;
 }
 
@@ -202,6 +215,14 @@ export interface PaintingCheckupData {
 export const api = {
   getBounds: () => fetchJson<YearBounds>(`${API}/bounds`),
 
+  getCatalogBootstrap: (start?: number, end?: number) => {
+    const params = new URLSearchParams();
+    if (start != null) params.set('start', String(start));
+    if (end != null) params.set('end', String(end));
+    const qs = params.toString();
+    return fetchJson<CatalogBootstrap>(`${API}/catalog/bootstrap${qs ? `?${qs}` : ''}`);
+  },
+
   getTimeline: (start: number, end: number) =>
     fetchJson<TimelineData>(`${API}/timeline?start=${start}&end=${end}`),
 
@@ -345,6 +366,8 @@ export const api = {
       }
       return res.json() as Promise<{ checked: boolean; fixed: boolean }>;
     }),
+
+  preloadArtistImages,
 };
 
 export function debugImageProxyUrl(