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>

tests/test_editor_dock_detach_placement.py

@@ -0,0 +1,25 @@
+"""The dock groups no longer expose a tear-off / undock control."""
+
+import re
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[1]
+DOCK_JS = (ROOT / "static/js/editor/build/dock.js").read_text()
+SW_JS = (ROOT / "static/sw.js").read_text()
+
+
+def test_group_undock_control_is_removed():
+    assert "ge-dock-detach" not in DOCK_JS
+    assert "Undock panel group" not in DOCK_JS
+    assert "activeItem.after(detach);" not in DOCK_JS
+    assert "detachPlacers.set(" not in DOCK_JS
+
+
+def test_per_tab_tearoff_glyph_is_removed():
+    assert "ge-dock-tab-pop" not in DOCK_JS
+    assert "item.appendChild(pop);" not in DOCK_JS
+
+
+def test_sw_cache_name_is_versioned():
+    m = re.search(r"CACHE_NAME = '([^']+)'", SW_JS)
+    assert m and re.fullmatch(r"odysseus-v\d+-pr40-editor-precache", m.group(1))