v2.1

Fixed

• DB now lives in the /config volume rather than the recordings
  mount for better performance when the recordings are on
  slower storage.
• The startup retention sweep runs in the background rather than
  blocking the UI when there's a large delete backlog.

Changed

• Retention sweep logs progress: a header when the time-phase has
  work, then a line every 10 deletions. Previously silent until the
  end-of-sweep summary.

Migration

• An existing DB at ${RECORDINGS}/.viofosync.db is copied to
  ${CONFIG_DIR}/viofosync.db on first boot under v2.1. The legacy
  file is renamed to .viofosync.db.migrated on the recordings
  volume as a recoverable fallback.