feat(store): task schedule columns, run trigger, scheduling queries

migrations/0004_task_scheduling.up.sql

@@ -0,0 +1,4 @@
+ALTER TABLE tasks ADD COLUMN schedule_interval_seconds INT NOT NULL DEFAULT 0;
+ALTER TABLE tasks ADD COLUMN schedule_anchor TIMESTAMPTZ;
+ALTER TABLE tasks ADD COLUMN broken BOOLEAN NOT NULL DEFAULT false;
+ALTER TABLE runs  ADD COLUMN trigger TEXT NOT NULL DEFAULT 'manual';