Add debug Remove entry, Show more auto-picker, and update docs.

DELETE /api/paintings/:id removes works and image files with gallery refresh and catalog navigation; Show more opens the search modal on load; documentation updated for migrate schema and debug workflow.

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

client/src/components/PaintingDetail.css

@@ -540,6 +540,10 @@
   margin-top: 0;
 }
 
+.debug-action-buttons-danger {
+  margin-top: 4px;
+}
+
 .debug-clear-btn,
 .debug-upload-btn {
   flex: 1;
@@ -578,6 +582,27 @@
   cursor: wait;
 }
 
+.debug-remove-btn {
+  width: 100%;
+  padding: 8px 10px;
+  border-radius: 6px;
+  font-size: 12px;
+  font-weight: 600;
+  cursor: pointer;
+  border: 1px solid rgba(200, 60, 60, 0.65);
+  background: rgba(200, 60, 60, 0.12);
+  color: #e05050;
+}
+
+.debug-remove-btn:hover:not(:disabled) {
+  background: rgba(200, 60, 60, 0.22);
+}
+
+.debug-remove-btn:disabled {
+  opacity: 0.6;
+  cursor: wait;
+}
+
 .painting-frame-empty {
   min-height: 280px;
   cursor: default;