feat(photo-editor): Ajax Image Editor client (Photoshop-parity tools)

Photoshop-parity editor client: layers, selection/masking, brushes,
smart filters, LUT import, Quick Edit, mobile gestures, workspaces,
batch operations, and the service-worker versioning (v978->v1006).

Source: vendor/photocraft (ad1cff44) photo-editor client files, merged
onto upstream/dev (a8c147b2). Conflict resolution documented in
pr_work/A_conflicts.md; editor files taken from vendor/photocraft
(upstream's editor is an earlier snapshot of the same feature).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

static/js/editor/tools/pen-path.js

@@ -0,0 +1,68 @@
+/**
+ * Vector pen / path tool — click to drop anchors, double-click (or the
+ * Finish button / Enter) to close the path. The draft is rendered live as
+ * a `shape` layer of type `path`; the caller owns layer creation, geometry
+ * updates and cleanup so this module stays free of editor state.
+ */
+
+export function createPenPathTool({
+  saveState = () => {},
+  canvasCoords = () => ({ x: 0, y: 0 }),
+  mainCanvas = null,
+  ensurePathLayer = () => null,
+  drawPath = () => {},
+  commitPath = () => {},
+  cancelPath = () => {},
+  composite = () => {},
+  syncToolClearIndicators = () => {},
+} = {}) {
+  let draft = null;
+
+  function addPoint(e) {
+    const point = canvasCoords(e, mainCanvas);
+    if (!Number.isFinite(point?.x) || !Number.isFinite(point?.y)) return false;
+    if (!draft) {
+      saveState('Add path');
+      const layer = ensurePathLayer();
+      if (!layer) return false;
+      draft = { layer, points: [point] };
+    } else {
+      draft.points.push(point);
+    }
+    drawPath(draft.layer, draft.points);
+    composite();
+    return true;
+  }
+
+  function begin(e) {
+    addPoint(e);
+    if (e && e.detail >= 2) finish();
+    return true;
+  }
+
+  function drag() {}
+  function end() {}
+
+  function finish() {
+    if (!draft) return false;
+    if (draft.points.length >= 2) {
+      commitPath(draft.layer, draft.points);
+    } else {
+      cancelPath(draft.layer);
+    }
+    draft = null;
+    composite();
+    syncToolClearIndicators();
+    return true;
+  }
+
+  function cancel() {
+    if (!draft) return false;
+    cancelPath(draft.layer);
+    draft = null;
+    composite();
+    return true;
+  }
+
+  return { begin, drag, end, finish, cancel, hasDraft: () => !!draft };
+}