Improve 3D gallery and debug checkup workflow for image curation.

Add parquet floor, museum-style exit, movement-tinted walls, and gold/black
frames with gallery sync after Fix it. Debug panel gets Checked and Fix it
buttons; documentation and image-fetch reliability updates included.

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

client/src/components/PaintingDetail.css

@@ -440,6 +440,34 @@
   word-break: break-word;
 }
 
+.debug-action-buttons {
+  display: flex;
+  gap: 8px;
+  margin-top: 4px;
+}
+
+.debug-checked-btn {
+  flex: 1;
+  padding: 8px 10px;
+  border: 1px solid rgba(201, 169, 110, 0.45);
+  border-radius: 6px;
+  background: rgba(201, 169, 110, 0.1);
+  color: #c9a96e;
+  font-size: 12px;
+  font-weight: 600;
+  cursor: pointer;
+}
+
+.debug-checked-btn:hover:not(:disabled) {
+  background: rgba(201, 169, 110, 0.22);
+  border-color: #c9a96e;
+}
+
+.debug-checked-btn:disabled {
+  opacity: 0.55;
+  cursor: default;
+}
+
 .debug-image-preview {
   display: block;
   width: 100%;
@@ -451,7 +479,7 @@
 }
 
 .debug-fix-btn {
-  width: 100%;
+  flex: 1;
   padding: 8px 10px;
   border: 1px solid #e8a040;
   border-radius: 6px;