feat(admin): offer background removal where an item's photos are edited (#293)

One button per item in the inventory editor, beside the per-thumbnail delete buttons rather than on them, because an upload is one item and its photos are views of one thing.

Its label is derived from the images rather than stored: Restore originals when every photo already carries an original, Remove backgrounds otherwise. The otherwise deliberately covers the mixed state a partial failure leaves behind — with two of four cut out it reads Remove backgrounds, which is the action that finishes the job, and pressing it skips the two that already worked.

Rendering is gated on the feature being configured or every photo already being cut out, not on the flag alone. Gating on the flag would hide Restore originals the moment REMBG_URL is unset, stranding cut-out photos with no way back — the same reasoning the review queue's control already uses.

The editor is a modal and this changes files on the server while it is open, so the item is re-read afterwards and the open modal updated. Without that the thumbnails keep showing the previous files and the button looks like it did nothing, which is the bug this was most likely to ship with.

frontend/src/api.ts gains original_image_path on the shared Item type's images, since ADMIN_ITEM_SELECT's images aggregate carries it and the public catalogue's does not. It is added as optional rather than required because Item is the same type fetchItems() uses for the public storefront, and a required field the public response never sends would be a type that lies about what is actually there.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

frontend/src/admin/Admin.tsx

@@ -66,6 +66,11 @@ function Inventory() {
   const [tags, setTags] = useState<TagRecord[]>([]);
   const [saving, setSaving] = useState(false);
   const [filters, setFilters] = useState<ItemFilters>(EMPTY_FILTERS);
+  // Whether this environment has a background-removal sidecar. False hides the
+  // control rather than offering one that would report zero of four done every
+  // time — an unconfigured environment is a working one, not a broken one.
+  const [backgroundRemoval, setBackgroundRemoval] = useState(false);
+  const [busyBackgrounds, setBusyBackgrounds] = useState(false);
   const { mode } = useThemeMode();
 
   // Typing in the price fields fires a request per keystroke, so responses can
@@ -91,7 +96,11 @@ function Inventory() {
   // from the sibling tabs, so they're refetched whenever the modal opens.
   const loadOptions = useCallback(() => Promise.all([
     fetchAdminCategories().then(setCategories),
-    fetchAdminTags().then(setTags)
+    fetchAdminTags().then(setTags),
+    fetch('/api/admin/config')
+      .then((res) => (res.ok ? res.json() : { backgroundRemoval: false }))
+      .then((config) => setBackgroundRemoval(config.backgroundRemoval))
+      .catch(() => setBackgroundRemoval(false))
   ]).catch(() => message.error('Could not load categories and tags')), []);
 
   // Refetch whenever the filters change — filtering is server-side so the
@@ -192,6 +201,49 @@ function Inventory() {
       : prev);
   }
 
+  /**
+   * Cut out every photo of the item being edited, or put every original back.
+   *
+   * Per item, not per photo: an upload is one item, and its photos are views of
+   * one thing (#293).
+   *
+   * The response replaces the open modal's images rather than being trusted to
+   * have changed nothing else. The editor is a modal and this changes files on
+   * the server while it is open, so without a refresh the thumbnails keep
+   * showing the previous files and the button looks like it did nothing.
+   */
+  async function handleBackgrounds(itemId: number, action: 'remove-backgrounds' | 'restore-originals') {
+    setBusyBackgrounds(true);
+    try {
+      const res = await fetch(`/api/admin/items/${itemId}/${action}`, { method: 'POST' });
+      if (!res.ok) {
+        message.error('That did not work.');
+        return;
+      }
+      const summary = await res.json();
+
+      if (action === 'remove-backgrounds' && summary.failed) {
+        // Said plainly rather than as a generic failure. How far it got is what
+        // decides whether pressing it again is worth anything, and it is —
+        // a retry skips the ones that already worked.
+        message.warning(`${summary.removed} of ${summary.total} photos done. Try again to finish.`);
+      } else {
+        message.success('Done.');
+      }
+
+      // Re-read the item so the thumbnails match what is now on the server.
+      const fresh = await fetch('/api/admin/items');
+      if (fresh.ok) {
+        const all: Item[] = await fresh.json();
+        const updated = all.find((candidate) => candidate.id === itemId);
+        if (updated) setEditingItem(prev => (prev && prev.id === itemId ? updated : prev));
+        setItems(all);
+      }
+    } finally {
+      setBusyBackgrounds(false);
+    }
+  }
+
   const columns = [
     {
       title: 'Image',
@@ -322,6 +374,24 @@ function Inventory() {
                     </div>
                   ))}
                 </Space>
+                {(backgroundRemoval || editingItem.images.every(img => img.original_image_path !== null)) && (
+                  <div style={{ marginTop: 8 }}>
+                    <Button
+                      size="small"
+                      loading={busyBackgrounds}
+                      onClick={() => void handleBackgrounds(
+                        editingItem.id,
+                        editingItem.images.every(img => img.original_image_path !== null)
+                          ? 'restore-originals'
+                          : 'remove-backgrounds'
+                      )}
+                    >
+                      {editingItem.images.every(img => img.original_image_path !== null)
+                        ? 'Restore originals'
+                        : 'Remove backgrounds'}
+                    </Button>
+                  </div>
+                )}
               </Form.Item>
             )}
             <Form.Item label={editingItem ? 'Add More Images' : 'Images (front, back, etc.)'}>