storage: multi-storage management with per-storage quota

Replace the single fixed /records path with a list of storages and an
active selection (where new recordings go). Quota is now per-storage.

- config: StorageItem(id,name,type,path,quota_gb,nas-meta) + Storage keeps
  global retention_days/segment_seconds; active + items. Migration from the
  old single {path,quota_gb} schema → one local item.
- recorder: write to the active storage; restart_all() repoints on switch;
  NAS-not-mounted guard (never write into the container overlay).
- indexer: scan ALL storage roots so recordings survive an active switch.
- retention: enforce quota PER storage via db.total_size_under /
  oldest_recordings_under (path-prefix LIKE).
- api/storages: GET/POST/PUT/DELETE + activate + policy. NAS uses host-mount
  (backend stores SMB params, generates the mount/fstab command, reports
  ismount status). Retire old POST /api/storage.
- frontend: new "Хранилища" settings tab — table with inline per-row quota,
  add form (local folder / NAS SMB), global policy (segment + retention).
- compose: add shared ./storages:/storages root for extra local folders and
  host-mounted NAS shares.

VERSION 0.0.127.

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

frontend/static/style.css

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   display: inline-flex; align-items: center; gap: 6px; padding: 2px 9px;
   border-radius: 11px; font-size: 12px; background: var(--panel-2);
 }
+.badge-active { background: rgba(46, 204, 113, .18); color: var(--ok); font-weight: 600; }
+.q-cell { display: inline-flex; align-items: center; gap: 6px; }
+.q-cell .q-input { width: 78px; }
+.q-cell button { padding: 2px 8px; font-size: 12px; }
 .logbox {
   margin: 4px 10px 12px; padding: 10px; background: #05070a; border: 1px solid var(--border);
   border-radius: 6px; font-family: ui-monospace, "Cascadia Code", Consolas, monospace;