-- Operator-controlled kill switch for a library. When `enabled = 0` the
-- watcher tick skips that library entirely — before the availability
-- probe, before ingest, before any maintenance pass — and the orphan-GC
-- all-online check treats it as out-of-scope rather than as a blocker.
--
-- The intended workflow is staging a new mount: insert with enabled=0,
-- verify the row appears in /libraries with enabled=false, then UPDATE
-- to 1 to start ingest. Same toggle works as a maintenance kill switch
-- after the fact ("don't keep probing this NAS while I'm rebooting it").
--
-- Default 1 so every existing library stays running on upgrade — no
-- behavior change without an explicit flip.

ALTER TABLE libraries ADD COLUMN enabled BOOLEAN NOT NULL DEFAULT 1;