Add scheduled task automation skill with worker execution pipeline.

Introduce scheduled-task-automation for H5 and WeChat, persist tasks in h5_scheduled_tasks, and run due jobs via a dedicated worker that executes agent tasks and delivers results.

Co-authored-by: Cursor <cursoragent@cursor.com>

db.mjs

@@ -772,6 +772,37 @@ export async function migrateSchema(pool) {
     ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
   `);
 
+  await pool.query(`
+    CREATE TABLE IF NOT EXISTS h5_scheduled_tasks (
+      id CHAR(36) PRIMARY KEY,
+      user_id CHAR(36) NOT NULL,
+      title VARCHAR(200) NOT NULL,
+      task_spec TEXT NOT NULL,
+      recurrence ENUM('once', 'daily', 'weekly') NOT NULL DEFAULT 'daily',
+      hour TINYINT UNSIGNED NULL,
+      minute TINYINT UNSIGNED NOT NULL DEFAULT 0,
+      weekday TINYINT UNSIGNED NULL,
+      timezone VARCHAR(64) NOT NULL DEFAULT 'Asia/Shanghai',
+      next_run_at BIGINT NOT NULL,
+      last_run_at BIGINT NULL,
+      notify_channel ENUM('wechat', 'web', 'both') NOT NULL DEFAULT 'both',
+      status ENUM('active', 'locked', 'running', 'completed', 'failed', 'cancelled') NOT NULL DEFAULT 'active',
+      attempts INT NOT NULL DEFAULT 0,
+      locked_until BIGINT NULL,
+      last_error VARCHAR(500) NULL,
+      last_result_json JSON NULL,
+      source_channel ENUM('h5', 'wechat', 'agent', 'api') NOT NULL DEFAULT 'agent',
+      source_session_id VARCHAR(128) NULL,
+      source_message_id VARCHAR(128) NULL,
+      source_text TEXT NULL,
+      created_at BIGINT NOT NULL,
+      updated_at BIGINT NOT NULL,
+      KEY idx_scheduled_task_due (status, next_run_at),
+      KEY idx_scheduled_task_user (user_id, status, next_run_at),
+      CONSTRAINT fk_scheduled_task_user FOREIGN KEY (user_id) REFERENCES h5_users(id) ON DELETE CASCADE
+    ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci
+  `);
+
   await pool.query(`
     CREATE TABLE IF NOT EXISTS h5_schedule_delivery_logs (
       id CHAR(36) PRIMARY KEY,