docs/ops/image-background-removal-stack.md

@@ -2,7 +2,7 @@
 
 Setup notes for the Python image-processing stack behind the review queue's background-removal option.
 
-**Status: evaluated, not adopted.** The engine choice is still open — see the "Alternatives ruled out" section. Everything below was run and measured on 2026-09-02 against `danielgatis/rembg:latest`, on a Windows dev box under Docker Desktop. **The NAS is a different machine and will be slower**; treat these as an upper bound on capability, not a promise.
+**Status: adopted (#281).** The engine choice is settled — see "The one thing that must not be got wrong" below. Everything here was run and measured on 2026-09-02 against `danielgatis/rembg:latest`, on a Windows dev box under Docker Desktop. **The NAS is a different machine and will be slower**; treat these as an upper bound on capability, not a promise.
 
 ## Why a sidecar and not the host's Python
 
@@ -88,8 +88,17 @@ curl -s -F "file=@any.jpg" -F "model=u2net" -o /dev/null http://localhost:7000/a
 
 **A hosted API** (remove.bg, Photoroom) — clear terms, no disk cost, best quality. Roughly $0.20 an image, another credential, another external dependency in the pipeline, and would want the budget ceiling that #227 gave submissions.
 
-## If this is adopted
+## How the application uses it
 
-The application would `POST` to the sidecar rather than doing any inference itself, which keeps every Python and ONNX dependency out of the Node image. Given 1–2 s warm, a synchronous request from the review queue is reasonable — unlike drafting, which was deliberately moved off the request path because a stranger can trigger it and must never wait.
+`backend/src/intake/rembgClient.ts` is the only thing that talks to the sidecar. It posts to `/api/remove` and **always sends `model=u2net`**; a unit test asserts that parameter is present, because nothing about the returned image would reveal its absence.
 
-The four design decisions already taken are independent of the engine: the cut-out replaces the item's image while the original is kept and restorable, the result is a transparent PNG, and the control sits on each photo in the review queue.
+`REMBG_URL` points at it — `http://rembg-syn:7000` on the NAS, where the container publishes `32700:7000`. The variable is optional in both compose files: unset means the submission page shows no checkbox, the review queue shows no control, and the drafting worker skips the step. An environment without a sidecar is a working environment.
+
+Two entry points, one module (`backend/src/intake/backgroundRemoval.ts`):
+
+- **The drafting worker**, honouring the checkbox on `/submit/:token`, which is ticked by default. The submitter's tick is recorded and acted on later, so nobody waits on a model run and an unreachable sidecar cannot fail an upload.
+- **The review queue**, per photo, synchronously — 1.1–2.3 s warm is a wait an admin who just clicked a button can absorb.
+
+Because removal follows drafting in the worker, an environment with no `ANTHROPIC_API_KEY` drafts nothing and so cuts out nothing. The per-photo control in the review queue is the way to do it by hand there.
+
+The original file is never destroyed. `item_images.original_image_path` records where it went, and **Restore original** swaps it back. Nothing in the feature deletes a file or a row.

frontend/src/admin/DraftQueue.tsx

@@ -10,7 +10,15 @@ import Empty from 'antd/es/empty';
 import Alert from 'antd/es/alert';
 import Modal from 'antd/es/modal';
 import message from 'antd/es/message';
-import { Draft, PriceSource, actOnDraft, fetchDrafts, publishDraft } from './draftsApi';
+import {
+  Draft,
+  DraftImage,
+  PriceSource,
+  actOnDraft,
+  fetchDrafts,
+  publishDraft,
+  setImageBackground
+} from './draftsApi';
 
 const { TextArea } = Input;
 
@@ -25,6 +33,54 @@ function priceLabel(source: PriceSource): string {
   return 'default price — nobody chose this';
 }
 
+/**
+ * One photo, with the control that cuts it out or puts it back.
+ *
+ * Per photo rather than per item because that is how a poor result is undone:
+ * background removal produces the occasional bad cut on an unusual object, and
+ * the answer is to restore that one photograph, not to unpick the submission.
+ *
+ * The label is the state. `original_image_path` is the only thing consulted,
+ * so there is no second flag that could disagree with what the button does.
+ */
+function DraftPhoto({
+  image,
+  itemId,
+  enabled,
+  onChanged
+}: Readonly<{
+  image: DraftImage;
+  itemId: number;
+  enabled: boolean;
+  onChanged: () => void;
+}>) {
+  const [busy, setBusy] = useState(false);
+  const cutOut = image.original_image_path !== null;
+
+  const act = async () => {
+    setBusy(true);
+    try {
+      await setImageBackground(itemId, image.id, cutOut ? 'restore-original' : 'remove-background');
+      onChanged();
+    } catch (err) {
+      message.error(err instanceof Error ? err.message : 'that did not work');
+    } finally {
+      setBusy(false);
+    }
+  };
+
+  return (
+    <Space direction="vertical" size={4} align="center">
+      <img src={image.image_path} alt="" style={{ width: 120, height: 120, objectFit: 'cover' }} />
+      {enabled && (
+        <Button size="small" loading={busy} onClick={() => void act()}>
+          {cutOut ? 'Restore original' : 'Remove background'}
+        </Button>
+      )}
+    </Space>
+  );
+}
+
 /**
  * One submission, with everything needed to judge it.
  *
@@ -33,7 +89,11 @@ function priceLabel(source: PriceSource): string {
  * so — and 80.00 is a plausible price rather than an obvious sentinel, which is
  * exactly why it has to be called out rather than left to be noticed.
  */
-function DraftCard({ draft, onChanged }: Readonly<{ draft: Draft; onChanged: () => void }>) {
+function DraftCard({
+  draft,
+  backgroundRemoval,
+  onChanged
+}: Readonly<{ draft: Draft; backgroundRemoval: boolean; onChanged: () => void }>) {
   const [name, setName] = useState(draft.ai_name ?? draft.item_name);
   const [description, setDescription] = useState(
     draft.ai_description ?? draft.item_description ?? ''
@@ -82,13 +142,14 @@ function DraftCard({ draft, onChanged }: Readonly<{ draft: Draft; onChanged: ()
       <Space direction="vertical" style={{ width: '100%' }} size="middle">
         {draft.ai_error && <Alert type="warning" message={`Drafting failed: ${draft.ai_error}`} />}
 
-        <Space wrap>
+        <Space wrap align="start">
           {draft.images.map((image) => (
-            <img
+            <DraftPhoto
               key={image.id}
-              src={image.image_path}
-              alt=""
-              style={{ width: 120, height: 120, objectFit: 'cover' }}
+              image={image}
+              itemId={draft.item_id}
+              enabled={backgroundRemoval}
+              onChanged={onChanged}
             />
           ))}
         </Space>
@@ -148,12 +209,15 @@ function DraftCard({ draft, onChanged }: Readonly<{ draft: Draft; onChanged: ()
 
 export default function DraftQueue() {
   const [drafts, setDrafts] = useState<Draft[]>([]);
+  const [backgroundRemoval, setBackgroundRemoval] = useState(false);
   const [state, setState] = useState<string | undefined>(undefined);
   const [error, setError] = useState<string | null>(null);
 
   const load = useCallback(async () => {
     try {
-      setDrafts(await fetchDrafts(state));
+      const payload = await fetchDrafts(state);
+      setDrafts(payload.drafts);
+      setBackgroundRemoval(payload.backgroundRemoval);
       setError(null);
     } catch {
       setError('Could not load the review queue.');
@@ -188,7 +252,12 @@ export default function DraftQueue() {
       {error && <Alert type="error" message={error} />}
       {!error && drafts.length === 0 && <Empty description="Nothing waiting for review" />}
       {drafts.map((draft) => (
-        <DraftCard key={draft.item_id} draft={draft} onChanged={() => void load()} />
+        <DraftCard
+          key={draft.item_id}
+          draft={draft}
+          backgroundRemoval={backgroundRemoval}
+          onChanged={() => void load()}
+        />
       ))}
     </div>
   );

frontend/src/admin/draftsApi.ts

@@ -3,6 +3,12 @@ export type PriceSource = 'default' | 'ai' | 'admin';
 export interface DraftImage {
   id: number;
   image_path: string;
+  /**
+   * Where this photo came from, once it has been cut out. Null means it never
+   * was — which is also the answer to whether Restore has anything to do, so
+   * there is no second flag that could disagree with it.
+   */
+  original_image_path: string | null;
 }
 
 export interface Draft {
@@ -31,11 +37,21 @@ async function send(path: string, init?: RequestInit): Promise<Response> {
   });
 }
 
-export async function fetchDrafts(state?: string): Promise<Draft[]> {
+export interface DraftQueueResponse {
+  drafts: Draft[];
+  /**
+   * Whether a background-removal sidecar is configured. False hides the
+   * control rather than showing one that would answer 502 — an environment
+   * without a sidecar is a working environment.
+   */
+  backgroundRemoval: boolean;
+}
+
+export async function fetchDrafts(state?: string): Promise<DraftQueueResponse> {
   const query = state ? `?state=${encodeURIComponent(state)}` : '';
   const res = await send(query);
   if (!res.ok) throw new Error('could not load the review queue');
-  return (await res.json()).drafts;
+  return res.json();
 }
 
 export interface PublishInput {
@@ -71,3 +87,29 @@ export async function actOnDraft(
   const res = await send(`/${itemId}/${action}`, { method: 'POST' });
   if (!res.ok) throw new Error(`could not ${action} this draft`);
 }
+
+/**
+ * Cut one photo out, or put its original back.
+ *
+ * The server's message is preferred over a generic one for the same reason
+ * publishDraft prefers it: a 502 here says the removal service did not answer
+ * and the photo is unchanged, which is the difference between "try again" and
+ * "something is wrong with this item".
+ */
+export async function setImageBackground(
+  itemId: number,
+  imageId: number,
+  action: 'remove-background' | 'restore-original'
+): Promise<void> {
+  const res = await send(`/${itemId}/images/${imageId}/${action}`, { method: 'POST' });
+  if (res.ok) return;
+
+  let message = 'could not change this photo';
+  try {
+    message = (await res.json()).error ?? message;
+  } catch {
+    // A non-JSON body is a proxy or gateway error rather than the app
+    // refusing. The generic message is the honest thing to show.
+  }
+  throw new Error(message);
+}

frontend/tests/e2e/admin-draft-queue.spec.ts

@@ -98,4 +98,23 @@ test.describe('The review queue', () => {
     await dialog.getByRole('button', { name: 'Cancel', exact: true }).click();
     await expect(card.getByText(/nobody chose this/)).toBeVisible();
   });
+
+  // The control that makes a poor cut survivable. Its label is its state:
+  // "Remove background" until an original has been recorded, "Restore
+  // original" afterwards, read from one field rather than two that could
+  // disagree.
+  //
+  // Only the label is asserted, not a click. Pressing it would need a sidecar,
+  // and a test that depends on a service taking forty seconds to start is
+  // broken by construction — the swap itself is covered in the integration
+  // suite against a stub.
+  test('offers to remove the background on each photo', async ({ page, admin }) => {
+    const note = `Cutout ${RUN}`;
+    await submitAnItem(page, note);
+
+    await admin.open('Review queue');
+
+    const card = page.locator('.ant-card').filter({ hasText: note });
+    await expect(card.getByRole('button', { name: 'Remove background' })).toBeVisible();
+  });
 });