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_mobile_layers_sheet.py

@@ -0,0 +1,40 @@
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[1]
+CSS = ROOT / "static/css/13-image-editor.css"
+SW = ROOT / "static/sw.js"
+
+
+def _css():
+    return CSS.read_text(encoding="utf-8")
+
+
+def test_mobile_peek_bounds_the_whole_layers_section():
+    # The peek (collapsed) mobile sheet must bound the entire layers section,
+    # not just the list — otherwise the header/blend/list stop fitting and the
+    # add/fx/delete footer hangs below the viewport with no way to reach it.
+    css = _css()
+    assert ".ge-right-panel:not(.expanded) .ge-layers {" in css
+    assert "max-height: var(--peek-height, 110px);" in css
+
+
+def test_mobile_peek_layers_list_scrolls_internally():
+    css = _css()
+    assert ".ge-right-panel:not(.expanded) .ge-layers-list {" in css
+    assert "flex: 1 1 auto;" in css
+    assert "overflow-y: auto;" in css
+
+
+def test_mobile_peek_layers_list_is_not_centred_capped():
+    # The old rule capped the list at (peek - 52px) which let the section
+    # grow past the peek. That cap must be gone.
+    css = _css()
+    assert "max-height: calc(var(--peek-height, 110px) - 52px)" not in css
+
+
+def test_sw_cache_bumped():
+    # Version-agnostic: every commit bumps the SW cache.
+    import re
+    sw = SW.read_text(encoding="utf-8")
+    assert re.search(r"CACHE_NAME = 'odysseus-v\d+-pr40-editor-precache'", sw)