Improve 3D gallery UX, placeholders, and image accuracy.

Add multi-row dynamic halls, eye-level camera, canvas covers for missing works, preserved view when returning from detail, and corrected image overrides for Kauffman and Raphael. Update documentation and add fetched painting assets.

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

client/src/components/VirtualGallery.css

@@ -50,7 +50,8 @@
 }
 
 .gallery-back-btn,
-.gallery-bio-btn {
+.gallery-bio-btn,
+.gallery-exit-btn {
   padding: 8px 16px;
   border: 1px solid #c9a96e;
   background: rgba(201, 169, 110, 0.15);
@@ -62,8 +63,14 @@
   transition: background 0.2s;
 }
 
+.gallery-exit-btn {
+  border-color: #d4af37;
+  color: #f5e6c8;
+}
+
 .gallery-back-btn:hover,
-.gallery-bio-btn:hover {
+.gallery-bio-btn:hover,
+.gallery-exit-btn:hover {
   background: rgba(201, 169, 110, 0.35);
 }
 
@@ -71,6 +78,12 @@
   flex: 1;
   min-height: 0;
   position: relative;
+  cursor: grab;
+  touch-action: none;
+}
+
+.gallery-canvas-container.gallery-canvas-dragging {
+  cursor: grabbing;
 }
 
 .gallery-loading-overlay {
@@ -187,6 +200,11 @@
   pointer-events: none;
 }
 
+.gallery-exit-hint strong {
+  color: #d4af37;
+  font-weight: normal;
+}
+
 .gallery-exit-hint kbd {
   padding: 1px 6px;
   border: 1px solid rgba(201, 169, 110, 0.5);