chore: 将 frontend/dist 从版本控制中移除，补充 ElMessageBox 导入

- 移除 .gitignore 中对 frontend/dist/ 的例外规则，构建产物不再纳入版本控制
- DataProcessDetailView.vue 补充 ElMessageBox 导入修复 TS2552 错误

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

frontend/src/views/data-process/DataProcessDetailView.vue

@@ -1,7 +1,7 @@
 <script setup lang="ts">
 import { computed, onBeforeUnmount, onMounted, reactive, ref, watch } from 'vue'
 import { useRoute, useRouter } from 'vue-router'
-import { ElMessage } from 'element-plus'
+import { ElMessage, ElMessageBox } from 'element-plus'
 import PageCard from '@/components/PageCard.vue'
 import { usePolling } from '@/composables/usePolling'
 import {