Add movement gallery wings with period interiors and expand timeline features.

Movement galleries split large catalogs into chronological wings (~55 works), use era-themed 3D interiors with side-wall windows, wing navigator on the back exit, and front archways between wings. Also adds painting annotations, timeline event guides, portrait hover highlights, and documentation/API updates.

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

README.md

@@ -1,6 +1,6 @@
 # Art Gallery
 
-Interactive virtual art gallery: zoomable historical timeline with era click-to-zoom and major event markers, branching art-movement flow (curved streams, hover-to-reveal artist lifespans), one 3D hall per artist (parquet floor, movement-tinted walls, black/gold frames by review status, corridor layout for large catalogs, museum-style exit doors, golden influence lamps, canvas placeholders for missing works, influence-linked exits), painting detail with prev/next catalog browsing and fullscreen lightbox, debug-mode image audit on painting detail and artist bio (**Checked** / **Fix it** / **More** / **Clear** / **Upload**), Checkup page, preserved gallery camera on return, and Wikipedia-sourced artist biographies.
+Interactive virtual art gallery: zoomable historical timeline with era click-to-zoom, major event markers (vertical guides into the movement flow), branching art-movement streams (click a movement name to enter its **3D movement gallery** — period-themed wings with up to ~55 works each, side-wall windows, wing navigator), one 3D hall per artist (parquet floor, movement-tinted walls, black/gold frames by review status, corridor layout for large catalogs, museum-style exit doors, golden influence lamps, canvas placeholders for missing works, influence-linked exits), painting detail with art-history annotations, prev/next catalog browsing and fullscreen lightbox, debug-mode image audit on painting detail and artist bio (**Checked** / **Fix it** / **More** / **Clear** / **Upload**), Checkup page, preserved gallery camera on return, and Wikipedia-sourced artist biographies.
 
 ## Documentation
 
@@ -42,6 +42,8 @@ Interactive virtual art gallery: zoomable historical timeline with era click-to-
    npm run update-influences    # art-history lineage links between paintings
    npm run migrate:checkup-flags # review/fixed flags for Checkup + debug mode (paintings)
    npm run migrate:artist-checkup-flags # same flags for artist portraits (bio debug)
+   npm run migrate:painting-annotations # art-history notes on painting detail
+   npm run update-painting-annotations  # load curated notes (+ optional --wikipedia)
    npm run fetch-images -- --limit=50         # random batch of missing images (10s per work)
    npm run fetch-images -- --artist="Claude Monet"   # one artist in catalog order
    ```