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_bridge_js.py

@@ -0,0 +1,79 @@
+import json
+import subprocess
+import textwrap
+from pathlib import Path
+
+
+ROOT = Path(__file__).resolve().parents[1]
+MODULE = (ROOT / 'static/js/editor/editor-bridge.js').as_uri()
+
+
+def run_node(body):
+    script = textwrap.dedent(f"""
+        import {{ startEditorBridge, BRIDGE_VERSION }} from {json.dumps(MODULE)};
+        {body}
+    """)
+    result = subprocess.run(
+        ['node', '--input-type=module', '-e', script],
+        cwd=ROOT, text=True, capture_output=True, check=True,
+    )
+    return json.loads(result.stdout)
+
+
+def test_bridge_runs_queued_command_and_posts_result():
+    out = run_node("""
+        const calls = [];
+        const posts = [];
+        class FakeES {
+          constructor(url) { this.url = url; FakeES.last = this; }
+          close() { this.closed = true; }
+        }
+        const control = { invoke(op, params) {
+          calls.push(op);
+          if (op === 'screenshot') return { ok: true, result: { dataUrl: 'data:image/png;base64,ZZ' } };
+          return { ok: true, result: 'r:' + op };
+        } };
+        const fetchImpl = async (url, opts) => { posts.push({ url, body: JSON.parse(opts.body) }); return { ok: true, json: async () => ({ ok: true }) }; };
+        const bridge = startEditorBridge({ control, session: 's1', baseUrl: '/x', EventSourceImpl: FakeES, fetchImpl });
+        FakeES.last.onmessage({ data: JSON.stringify({ id: 'c1', op: 'history.undo', params: {} }) });
+        await new Promise(r => setTimeout(r, 25));
+        console.log(JSON.stringify({ esUrl: FakeES.last.url, calls, posts, session: bridge.session, version: BRIDGE_VERSION }));
+    """)
+    assert out['esUrl'] == '/x/api/editor/bridge/events?session=s1'
+    assert 'history.undo' in out['calls']
+    assert 'screenshot' in out['calls']
+    assert out['posts'][0]['url'] == '/x/api/editor/bridge/result'
+    assert out['posts'][0]['body']['id'] == 'c1'
+    assert out['posts'][0]['body']['ok'] is True
+    assert out['posts'][0]['body']['screenshot'].startswith('data:image/png')
+    assert out['session'] == 's1'
+    assert out['version'] == '1.0'
+
+
+def test_bridge_reports_op_failure_and_stop_closes_stream():
+    out = run_node("""
+        const posts = [];
+        class FakeES {
+          constructor(url) { this.url = url; FakeES.last = this; }
+          close() { this.closed = true; }
+        }
+        const control = { invoke(op) {
+          if (op === 'screenshot') return { ok: true, result: { dataUrl: 'data:image/png;base64,ZZ' } };
+          return { ok: false, error: 'nope' };
+        } };
+        const fetchImpl = async (url, opts) => { posts.push(JSON.parse(opts.body)); return { ok: true, json: async () => ({}) }; };
+        const bridge = startEditorBridge({ control, session: 'default', EventSourceImpl: FakeES, fetchImpl });
+        FakeES.last.onmessage({ data: JSON.stringify({ id: 'x', op: 'layers.delete', params: { id: 'layer-9' } }) });
+        await new Promise(r => setTimeout(r, 25));
+        bridge.stop();
+        console.log(JSON.stringify({ body: posts[0], closed: !!FakeES.last.closed }));
+    """)
+    assert out['body']['ok'] is False
+    assert out['body']['error'] == 'nope'
+    assert out['body']['result'] is None
+    assert out['closed'] is True
+
+
+def test_bridge_module_is_precached_for_offline_use():
+    sw = (ROOT / 'static/sw.js').read_text(encoding='utf-8')
+    assert "'/static/js/editor/editor-bridge.js'" in sw