feat(organize/scan): transfer modes, seeding-safe relocation, inode dedup, incremental scanning

- Organizer: add move/copy/hardlink/symlink transfer modes (default move),
  per-request target_path/transfer_mode overrides, and honor organize.target_dir
  / organize.transfer_mode settings.
- keep_seeding (default on): escalate move->hardlink (cross-device->copy) so the
  qBittorrent source stays in place and continues seeding after organize.
- qBittorrent SetLocation + POST /downloads/relocate to migrate whole torrents
  while keeping them seeding.
- Scanner: FileID (device:inode) hardlink dedup to avoid duplicate recognition
  and double-counted storage; extract single-file ingest.
- Watcher: recursive watch + incremental per-file ingest/remove instead of full
  re-scan; periodic full library scan now gated behind scan.periodic_enabled
  (default off) to reduce disk wear.
- Telegram bot: handle callback_query in polling, declare allowed_updates in
  webhook, answer callbacks.
- Frontend: settings for transfer mode / keep_seeding / periodic scan; organize
  panel target dir + transfer mode overrides.
- Tests for transfer modes, organizer resolution, SetLocation, inode dedup,
  incremental ingest/remove.

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

internal/repository/repository.go

@@ -307,6 +307,10 @@ func (r *MediaRepository) Upsert(ctx context.Context, m *model.Media) error {
 		"container":    m.Container,
 		"deleted_at":   nil,
 	}
+	// 回填硬链接身份标识，便于后续扫描去重（避免重复识别/多倍占用）。
+	if m.FileID != "" && m.FileID != existing.FileID {
+		updates["file_id"] = m.FileID
+	}
 	if m.Title != "" {
 		// scanner 给出的标题只是从路径推导，刮削后 title 已被替换为
 		// 真实剧名。仅在 existing 还停留在 'pending'/'' 时回填扫描标题，