storage: per-camera target + date subfolders; move active-storage widget

- Camera.storage_id: each camera chooses its storage ("" = active/default).
  supervisor resolves per-camera (storage_by_id → active fallback); cameras
  API (body/payload) + /toggle accept storage_id and repoint the recorder.
- Recordings now go to <root>/<cam>/<YYYY-MM-DD>/<file>.mp4. This ffmpeg build
  lacks -strftime_mkdir, so recorder_task pre-creates today+tomorrow dirs at
  start and the indexer re-ensures them each tick (survives midnight).
- indexer: scan date subdirs + legacy flat files; sort by basename so the
  in-progress segment is detected correctly when both layouts coexist.
- frontend: per-camera "Хранилище" dropdown in the camera table (inline) and
  in the add/edit + bulk forms. Move the active-storage summary widget from
  the Система tab into the Хранилища tab.

VERSION 0.0.129.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

backend/app/config.py

@@ -19,6 +19,7 @@ class Camera:
     main_path: str
     sub_path: str | None = None
     record: bool = True   # REC: писать на диск. enabled — камера вообще включена (live+запись)
+    storage_id: str = ""  # в какое хранилище писать ("" = активное/по умолчанию)
 
     def rtsp_url(self, path: str) -> str:
         return f"rtsp://{self.user}:{self.password}@{self.ip}:554{path}"
@@ -141,6 +142,7 @@ def _camera_from_raw(c: dict) -> Camera:
         password=c["password"],
         main_path=c["main_path"],
         sub_path=c.get("sub_path"),
+        storage_id=c.get("storage_id", "") or "",
     )
 
 
@@ -198,6 +200,7 @@ def camera_to_yaml(c: Camera) -> dict:
         "password": c.password,
         "main_path": c.main_path,
         "sub_path": c.sub_path,
+        "storage_id": c.storage_id,
     }