Fix debug upload persistence and UX; exclude prod audit log from DB restore

Uploads and fixes now bust browser cache via file-mtime keys in API
responses. Debug upload shows a centered loading overlay and blocks search
while uploading. Prod DB restore skips curator_audit_log.

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

client/src/components/PaintingDetail.css

@@ -552,6 +552,48 @@
   font-size: 12px;
   font-weight: 600;
   cursor: pointer;
+  text-align: center;
+}
+
+.debug-upload-input {
+  position: absolute;
+  width: 1px;
+  height: 1px;
+  padding: 0;
+  margin: -1px;
+  overflow: hidden;
+  clip: rect(0, 0, 0, 0);
+  white-space: nowrap;
+  border: 0;
+}
+
+.debug-upload-btn-disabled {
+  opacity: 0.6;
+  cursor: wait;
+  pointer-events: none;
+}
+
+.debug-upload-btn-loading {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  gap: 6px;
+}
+
+.debug-upload-page-overlay.gallery-loading-marker-overlay {
+  position: fixed;
+  inset: 0;
+  z-index: 300;
+}
+
+.painting-frame-uploading,
+.bio-portrait-uploading {
+  min-height: 240px;
+}
+
+.debug-image-panel.debug-image-panel-blocked {
+  opacity: 0.55;
+  pointer-events: none;
 }
 
 .debug-clear-btn {
@@ -576,8 +618,7 @@
   border-color: #8cbe8c;
 }
 
-.debug-clear-btn:disabled,
-.debug-upload-btn:disabled {
+.debug-clear-btn:disabled {
   opacity: 0.6;
   cursor: wait;
 }