-- ============ jobs（DB-backed 事件型任务） ============
CREATE TABLE jobs (
  id            UUID PRIMARY KEY,
  type          TEXT NOT NULL,
  payload       JSONB NOT NULL DEFAULT '{}'::jsonb,
  status        TEXT NOT NULL DEFAULT 'pending',
  scheduled_at  TIMESTAMPTZ NOT NULL DEFAULT now(),
  attempts      INT  NOT NULL DEFAULT 0,
  max_attempts  INT  NOT NULL DEFAULT 5,
  leased_at     TIMESTAMPTZ,
  leased_by     TEXT,
  last_error    TEXT,
  completed_at  TIMESTAMPTZ,
  created_at    TIMESTAMPTZ NOT NULL DEFAULT now(),
  updated_at    TIMESTAMPTZ NOT NULL DEFAULT now(),
  CONSTRAINT jobs_status_check CHECK (status IN ('pending','running','completed','dead'))
);
CREATE INDEX idx_jobs_pickup ON jobs(scheduled_at, status) WHERE status = 'pending';
CREATE INDEX idx_jobs_lease  ON jobs(leased_at) WHERE status = 'running';
CREATE INDEX idx_jobs_purge  ON jobs(completed_at) WHERE status IN ('completed', 'dead');

-- ============ ALTER workspace_worktrees: add prune_warning_at ============
ALTER TABLE workspace_worktrees
  ADD COLUMN prune_warning_at TIMESTAMPTZ;