Tables and indexes per spec §5. session_vector_at_play ships nullable
so M3 doesn't need a follow-up migration. Table is named play_sessions
to avoid collision with the existing sessions (HTTP auth) table from
migration 0004.
Stores sha256(token) plus user_agent + last_seen_at so future
active-sessions UI doesn't need another migration.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Subsonic token auth (t=md5(password+salt)) needs a reversibly stored
credential; bcrypt password_hash can't serve. NULL means the user has
not opted in, forcing apiKey (OpenSubsonic) instead.
bvandeusen