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_head_buttons.py

@@ -0,0 +1,35 @@
+import re
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parent.parent
+DOCK_JS = (ROOT / "static/js/editor/build/dock.js").read_text(encoding="utf-8")
+CSS = (ROOT / "static/css/13-image-editor.css").read_text(encoding="utf-8")
+SW = (ROOT / "static/sw.js").read_text(encoding="utf-8")
+
+
+def test_dock_head_button_glyphs_are_16px():
+    # The group-head buttons (collapse/expand, more) use the same 16px glyph
+    # as the float-window dock button. (The group detach glyph was removed.)
+    assert DOCK_JS.count('width="16" height="16"') >= 4
+    assert 'width="11" height="11"' not in DOCK_JS
+
+
+def test_dock_head_buttons_match_float_dock_size():
+    for cls in (".ge-dock-collapse {", ".ge-dock-detach {", ".ge-dock-tabs-more {"):
+        idx = CSS.index(cls)
+        block = CSS[idx:idx + 240]
+        assert "width: 26px;" in block, cls
+        assert "height: 26px;" in block, cls
+        assert "padding: 0;" in block, cls
+
+
+def test_dock_head_svg_rule_present():
+    assert (
+        ".ge-dock-collapse svg, .ge-dock-detach svg, .ge-dock-tabs-more svg "
+        "{ width: 16px; height: 16px; flex: 0 0 auto; }" in CSS
+    )
+
+
+def test_sw_cache_name_bumped():
+    m = re.search(r"CACHE_NAME\s*=\s*'([^']+)'", SW)
+    assert m and re.fullmatch(r"odysseus-v\d+-pr40-editor-precache", m.group(1))