feat(调度任务): 实现调度任务管理功能

新增调度任务模块，支持任务的增删改查、启停及手动执行
- 后端添加 schedule_job 模型、服务、路由及调度器工具类
- 前端新增调度任务管理页面
- 修改 flow 相关接口将 id 类型从 String 改为 i64
- 添加 tokio-cron-scheduler 依赖实现定时任务调度
- 初始化时加载已启用任务并注册到调度器

.trae/rules/examples/job_service.rs

@@ -0,0 +1,124 @@
+//! 模块：定时任务服务（Service Layer）
+//! 职责：
+//! 1) 负责定时任务（schedule_jobs）的数据库增删改查；
+//! 2) 在创建/更新/删除后与调度器同步；
+//! 3) 服务启动时加载已启用任务并注册。
+
+use std::{future::Future, pin::Pin, sync::Arc};
+
+use chrono::{DateTime, FixedOffset, Utc};
+use sea_orm::{ActiveModelTrait, ColumnTrait, EntityTrait, QueryFilter, QueryOrder, Set};
+use tokio_cron_scheduler::Job;
+use tracing::{error, info};
+
+use crate::{db::Db, error::AppError, models::schedule_job, utils};
+
+/// 通用分页响应体
+#[derive(serde::Serialize)]
+pub struct PageResp<T> {
+    pub items: Vec<T>,
+    pub total: u64,
+    pub page: u64,
+    pub page_size: u64,
+}
+
+/// 任务文档（对外返回 DTO）
+#[derive(serde::Deserialize, serde::Serialize, Clone, Debug)]
+pub struct ScheduleJobDoc {
+    pub id: i64,
+    pub name: String,
+    pub cron_expr: String,
+    pub enabled: bool,
+    pub flow_code: String,
+    pub created_at: DateTime<FixedOffset>,
+    pub updated_at: DateTime<FixedOffset>,
+}
+
+impl From<schedule_job::Model> for ScheduleJobDoc {
+    fn from(m: schedule_job::Model) -> Self {
+        Self {
+            id: m.id,
+            name: m.name,
+            cron_expr: m.cron_expr,
+            enabled: m.enabled,
+            flow_code: m.flow_code,
+            created_at: m.created_at,
+            updated_at: m.updated_at,
+        }
+    }
+}
+
+/// 创建任务请求体
+#[derive(serde::Deserialize)]
+pub struct CreateReq {
+    pub name: String,
+    pub cron_expr: String,
+    pub enabled: bool,
+    pub flow_code: String,
+}
+
+/// 获取当前 UTC 时间并转为固定偏移
+fn now_fixed_offset() -> DateTime<FixedOffset> {
+    Utc::now().with_timezone(&FixedOffset::east_opt(0).unwrap())
+}
+
+/// 创建任务
+pub async fn create(db: &Db, req: CreateReq) -> Result<ScheduleJobDoc, AppError> {
+    // 1) 校验 cron 表达式
+    Job::new_async(&req.cron_expr, |_id, _l| Box::pin(async {}))
+        .map_err(|e| AppError::BadRequest(format!("无效的 cron 表达式: {e}")))?;
+
+    // 2) 入库
+    let am = schedule_job::ActiveModel {
+        id: Set(crate::utils::generate_id()),
+        name: Set(req.name),
+        cron_expr: Set(req.cron_expr),
+        enabled: Set(req.enabled),
+        flow_code: Set(req.flow_code),
+        created_at: Set(now_fixed_offset()),
+        updated_at: Set(now_fixed_offset()),
+    };
+    let m = am.insert(db).await?;
+
+    // 3) 同步调度器
+    let executor = build_executor_for_job(db, &m);
+    utils::add_or_update_job_by_model(&m, executor).await.map_err(AppError::Anyhow)?;
+
+    Ok(m.into())
+}
+
+/// 构建任务执行闭包（JobExecutor）
+fn build_executor_for_job(db: &Db, m: &schedule_job::Model) -> utils::JobExecutor {
+    let db = db.clone();
+    let job_id = m.id;
+    let job_name = m.name.clone();
+
+    Arc::new(move || {
+        let db = db.clone();
+        let job_id = job_id;
+        let job_name = job_name.clone();
+
+        Box::pin(async move {
+            match schedule_job::Entity::find_by_id(job_id).one(&db).await {
+                Ok(Some(model)) if !model.enabled => {
+                    info!(target = "udmin", job = %job_name, id = %job_id, "scheduler.tick.skip");
+                    return;
+                }
+                Ok(None) => {
+                    info!(target = "udmin", job = %job_name, id = %job_id, "scheduler.tick.deleted");
+                    if let Err(e) = utils::remove_job_by_id(&job_id).await {
+                        error!(target = "udmin", id = %job_id, error = %e, "scheduler.self_remove.failed");
+                    }
+                    return;
+                }
+                Err(e) => {
+                    error!(target = "udmin", job = %job_name, id = %job_id, error = %e, "scheduler.tick.error");
+                    return;
+                }
+                _ => {}
+            }
+
+            info!(target = "udmin", job = %job_name, "scheduler.tick.start");
+        }) as Pin<Box<dyn Future<Output = ()> + Send>>
+    })
+}