CREATE TABLE system_schedules (
    id          TEXT PRIMARY KEY,
    schedule    TEXT NOT NULL,
    next_run_at TEXT NOT NULL,
    last_run_at TEXT
) STRICT;

-- Seed the fixed set of system schedules. The schedule column is authoritative
-- thereafter; the runner holds only the id->task dispatch. next_run_at is set
-- to now so each fires once on first boot after this migration, then settles
-- onto its schedule.
INSERT INTO system_schedules (id, schedule, next_run_at) VALUES
    ('prune_sessions', 'daily 03:00', datetime('now')),
    ('prune_tokens',   'daily 04:00', datetime('now'));