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_overflow_glyph.py

@@ -0,0 +1,28 @@
+"""The dock tab-strip overflow control shows an ellipsis, not a chevron."""
+import re
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[1]
+
+
+def _read(rel):
+    return (ROOT / rel).read_text(encoding="utf-8")
+
+
+def test_overflow_control_uses_ellipsis():
+    dock = _read("static/js/editor/build/dock.js")
+    assert '<circle cx="6" cy="12" r="1.9"/>' in dock
+    assert '<circle cx="12" cy="12" r="1.9"/>' in dock
+    assert '<circle cx="18" cy="12" r="1.9"/>' in dock
+
+
+def test_right_chevron_removed_from_dock():
+    dock = _read("static/js/editor/build/dock.js")
+    assert 'polyline points="9 6 15 12 9 18"' not in dock
+
+
+def test_sw_cache_name_is_versioned():
+    sw = _read("static/sw.js")
+    m = re.search(r"CACHE_NAME = '([^']+)'", sw)
+    assert m is not None
+    assert re.fullmatch(r"odysseus-v\d+-pr40-editor-precache", m.group(1))