Add public curator notes and U-shaped hall wall hang.

Paintings get editable curator notes with brass plates in the 3D hall, and visit order now uses the far/end wall between left and right.

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

Documentation/i18n-russian.md

@@ -69,7 +69,7 @@ API (curator-only): see [API.md](API.md#translations-curator).
 | `era`, `movement` | `name`, `description` |
 | `artist` | `name`, `bio_short`, `bio_full` |
 | `artist_period` | `name`, `description` |
-| `painting` | `title`, `description` |
+| `painting` | `title`, `description` (not `curator_notes` — English-only for now) |
 | `annotation` | `label`, `body` |
 | `influence_source` | `notes`, `aspects`, `quote`, `period_note` |