feat(任务调度): 增加任务开始和结束时间字段，优化任务调度逻辑

- 在任务类型、模型、接口和前端页面中新增 `start_date` 和 `end_date` 字段
- 优化任务调度逻辑，支持根据开始和结束时间设置任务的执行时间
- 前端新增间隔时间设置组件和 Cron 表达式选择器，提升用户体验
- 更新依赖包，引入 `element-plus` 和 `vue3-cron-plus-picker` 组件

frontend/package-lock.json

@@ -13,6 +13,7 @@
         "ant-design-vue": "^4.2.5",
         "axios": "^1.6.7",
         "echarts": "^5.5.0",
+        "element-plus": "^2.8.4",
         "highlight.js": "^11.10.0",
         "json-viewer-js": "^1.0.8",
         "md5": "^2.3.0",
@@ -25,6 +26,7 @@
         "vue-request": "^2.0.4",
         "vue-router": "^4.2.5",
         "vue3-cron-plus": "^0.1.9",
+        "vue3-cron-plus-picker": "^1.0.2",
         "vuex": "^4.1.0",
         "xlsx": "^0.18.5"
       },
@@ -1533,9 +1535,9 @@
       }
     },
     "node_modules/element-plus": {
-      "version": "2.9.5",
-      "resolved": "https://registry.npmmirror.com/element-plus/-/element-plus-2.9.5.tgz",
-      "integrity": "sha512-r+X79oogLbYq8p9L5f9fHSHhUFNM0AL72aikqiZVxSc2/08mK6m/PotiB9e/D90QmWTIHIaFnFmW65AcXmneig==",
+      "version": "2.9.7",
+      "resolved": "https://registry.npmmirror.com/element-plus/-/element-plus-2.9.7.tgz",
+      "integrity": "sha512-6vjZh5SXBncLhUwJGTVKS5oDljfgGMh6J4zVTeAZK3YdMUN76FgpvHkwwFXocpJpMbii6rDYU3sgie64FyPerQ==",
       "license": "MIT",
       "dependencies": {
         "@ctrl/tinycolor": "^3.4.1",
@@ -3003,6 +3005,12 @@
         "vue": "^3.2.13"
       }
     },
+    "node_modules/vue3-cron-plus-picker": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmmirror.com/vue3-cron-plus-picker/-/vue3-cron-plus-picker-1.0.2.tgz",
+      "integrity": "sha512-SUVmAb2qSPMuAm5GIU0wQZyUawiiL3OKEy1HAZs94eZz+neKF+wEPNP4wICWMU78u4LzeCNni2Njnhf8bsqkcw==",
+      "license": "ISC"
+    },
     "node_modules/vuex": {
       "version": "4.1.0",
       "resolved": "https://registry.npmmirror.com/vuex/-/vuex-4.1.0.tgz",