feat(photo-editor): NL editor planner, image ops, email/gallery server

Server-side photo editor: natural-language editor agent route
(/api/editor/agent), photo_editor tool family + style guide, image-op
provider proxy with progress, email server hardening, gallery/hwfit
routes, and graceful shutdown.

Source: vendor/photocraft (ad1cff44) editor-server files, merged onto
upstream/dev (a8c147b2). Conflict resolution documented in
pr_work/B_conflicts.md.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/activity.py

@@ -0,0 +1,61 @@
+"""In-flight activity counters (heavy image ops) for safe restarts/observability.
+
+A deploy restart kills any in-flight long image op (a diffusion edit is 60-120 s),
+so the operator needs to know whether the process is busy before issuing
+``systemctl --user restart``. These counters are process-local and cheap.
+"""
+from __future__ import annotations
+
+import threading
+import time
+from contextlib import contextmanager
+from typing import Dict
+
+_lock = threading.Lock()
+_image_ops = 0
+_image_ops_by_name: Dict[str, int] = {}
+_started_at = time.time()
+
+
+def begin_image_op(name: str = "image") -> None:
+    global _image_ops
+    with _lock:
+        _image_ops += 1
+        _image_ops_by_name[name] = _image_ops_by_name.get(name, 0) + 1
+
+
+def end_image_op(name: str = "image") -> None:
+    global _image_ops
+    with _lock:
+        _image_ops = max(0, _image_ops - 1)
+        if name in _image_ops_by_name:
+            _image_ops_by_name[name] -= 1
+            if _image_ops_by_name[name] <= 0:
+                _image_ops_by_name.pop(name, None)
+
+
+@contextmanager
+def image_op(name: str = "image"):
+    begin_image_op(name)
+    try:
+        yield
+    finally:
+        end_image_op(name)
+
+
+def activity() -> Dict[str, object]:
+    with _lock:
+        return {
+            "image_ops": _image_ops,
+            "image_ops_by_name": dict(_image_ops_by_name),
+            "uptime_s": round(time.time() - _started_at, 1),
+        }
+
+
+def heavy_image_ops_active() -> int:
+    with _lock:
+        return _image_ops
+
+
+def busy() -> bool:
+    return heavy_image_ops_active() > 0