增加打手登录设备管理与三台设备限制

apps/backend/src/db/migrations/029_worker_sessions.sql

@@ -0,0 +1,27 @@
+-- 029_worker_sessions.sql —— 打手端登录设备会话。
+
+CREATE TABLE IF NOT EXISTS worker_sessions (
+  id BIGSERIAL PRIMARY KEY,
+  session_id TEXT NOT NULL UNIQUE,
+  worker_id BIGINT NOT NULL REFERENCES worker_users(id) ON DELETE CASCADE,
+  device_id TEXT NOT NULL DEFAULT '',
+  device_type TEXT NOT NULL DEFAULT 'pc',
+  device_name TEXT NOT NULL DEFAULT '',
+  user_agent TEXT NOT NULL DEFAULT '',
+  ip_address TEXT NOT NULL DEFAULT '',
+  status TEXT NOT NULL DEFAULT 'active',
+  issued_at TIMESTAMPTZ NOT NULL,
+  last_seen_at TIMESTAMPTZ NOT NULL,
+  expires_at TIMESTAMPTZ NOT NULL,
+  revoked_at TIMESTAMPTZ,
+  created_at TIMESTAMPTZ NOT NULL,
+  updated_at TIMESTAMPTZ NOT NULL
+);
+
+CREATE INDEX IF NOT EXISTS idx_worker_sessions_worker_status
+  ON worker_sessions(worker_id, status, expires_at DESC);
+CREATE INDEX IF NOT EXISTS idx_worker_sessions_worker_device
+  ON worker_sessions(worker_id, device_type, device_id, status);
+
+COMMENT ON TABLE worker_sessions IS '打手端登录会话与设备记录';
+COMMENT ON COLUMN worker_sessions.device_type IS '设备类型：pc、mobile 等；所有设备合计每个账号最多 3 台';