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_popup_placement.py

@@ -0,0 +1,37 @@
+import re
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parents[1]
+CSS = (ROOT / "static/css/13-image-editor.css").read_text(encoding="utf-8")
+GALLERY = (ROOT / "static/js/galleryEditor.js").read_text(encoding="utf-8")
+STUDIO = (ROOT / "static/js/editor/panels/studio-panels.js").read_text(encoding="utf-8")
+SW = (ROOT / "static/sw.js").read_text(encoding="utf-8")
+
+
+def test_tab_tear_off_icon_sits_inside_the_tab():
+    # The undock pop is absolutely positioned inside the tab item, not a sibling
+    # control that takes up its own space next to the tab.
+    item_block = CSS[CSS.index(".ge-dock-tab-item {"):CSS.index(".ge-dock-tab-pop {")]
+    assert "position: relative;" in item_block
+    pop_block = CSS[CSS.index(".ge-dock-tab-pop {"):CSS.index(".ge-dock-tab-pop {") + 400]
+    assert "position: absolute;" in pop_block
+    assert "right: 1px;" in pop_block
+
+
+def test_adjustment_grid_button_passes_itself_as_anchor():
+    assert "button.addEventListener('click', () => onAddAdjustment(type, button));" in STUDIO
+
+
+def test_on_add_adjustment_forwards_the_anchor():
+    assert "onAddAdjustment: (type, anchor) => {" in GALLERY
+    assert "anchor || document.getElementById('ge-add-fx')" in GALLERY
+
+
+def test_open_adj_popup_prefers_the_clicked_anchor():
+    assert "_openAdjPopup(layer, type, anchorEl || row, layer.adjustment);" in GALLERY
+
+
+def test_sw_cache_name_is_version_agnostic():
+    m = re.search(r"CACHE_NAME = '(odysseus-v\d+-pr40-editor-precache)'", SW)
+    assert m, "sw.js CACHE_NAME not found"
+    assert re.fullmatch(r"odysseus-v\d+-pr40-editor-precache", m.group(1))