feat: add 8 builtin tools, AgentSchedules management page, Celery Beat integration

- Add 3 schedule tools (create/list/delete) and 5 utility tools (crypto, random, email, URL, regex)
- Add frontend AgentSchedules.vue page with full CRUD, cron presets, manual trigger
- Integrate Celery Beat for automatic schedule execution
- Update startup scripts with Celery Beat launch
- Fix schedule list API to show all schedules for admin users
- Add celrybeat-schedule.* to .gitignore

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/components/MainLayout.vue

@@ -35,6 +35,10 @@
             <el-icon><ChatLineSquare /></el-icon>
             <span>Agent对话</span>
           </el-menu-item>
+          <el-menu-item index="agent-schedules" @click="router.push('/agent-schedules')">
+            <el-icon><Clock /></el-icon>
+            <span>定时任务</span>
+          </el-menu-item>
           <el-menu-item index="executions">
             <el-icon><List /></el-icon>
             <span>执行历史</span>
@@ -94,7 +98,7 @@
 import { computed } from 'vue'
 import { useRouter, useRoute } from 'vue-router'
 import { useUserStore } from '@/stores/user'
-import { Document, User, List, Connection, Setting, Star, Lock, Monitor, Bell, Grid, DataAnalysis, Tools } from '@element-plus/icons-vue'
+import { Document, User, List, Connection, Setting, Star, Lock, Monitor, Bell, Grid, DataAnalysis, Tools, Clock } from '@element-plus/icons-vue'
 
 const router = useRouter()
 const route = useRoute()
@@ -117,6 +121,7 @@ const activeMenu = computed(() => {
   if (route.path === '/agent-monitoring') return 'agent-monitoring'
   if (route.path === '/alert-rules') return 'alert-rules'
   if (route.path === '/agent-chat' || route.path.startsWith('/agent-chat/')) return 'agent-chat'
+  if (route.path === '/agent-schedules') return 'agent-schedules'
   return 'workflows'
 })
 
@@ -148,6 +153,8 @@ const handleMenuSelect = (key: string) => {
     router.push('/agent-monitoring')
   } else if (key === 'alert-rules') {
     router.push('/alert-rules')
+  } else if (key === 'agent-schedules') {
+    router.push('/agent-schedules')
   }
 }