feat(electron): 添加Electron桌面应用支持

- 新增Electron主进程、预加载脚本和构建配置
- 修改前端配置以支持Electron打包
- 更新项目文档和依赖
- 重构API调用使用统一axios实例

frontend/src/components/Dashboard.vue

@@ -77,7 +77,7 @@
 
 <script setup lang="ts">
 import { ref, computed, watch } from 'vue'
-import axios from 'axios'
+import api from '../utils/api'
 import { ElMessage } from 'element-plus'
 import { Refresh, Paperclip } from '@element-plus/icons-vue'
 import PinnedProject from './PinnedProject.vue'
@@ -275,7 +275,7 @@ const handleCrawl = async () => {
   }
   crawling.value = true
   try {
-    await axios.post('/api/crawler/run')
+    await api.post('/api/crawler/run')
     ElMessage.success('Crawl completed successfully')
     emit('refresh') // Refresh data after crawl
   } catch (error) {
@@ -301,7 +301,7 @@ const handlePinChanged = async (title: string) => {
 const togglePin = async (item: any) => {
   try {
     const newPinStatus = !item.pin
-    await axios.patch(`/api/bids/${encodeURIComponent(item.title)}/pin`, { pin: newPinStatus })
+    await api.patch(`/api/bids/${encodeURIComponent(item.title)}/pin`, { pin: newPinStatus })
     item.pin = newPinStatus
     ElMessage.success(newPinStatus ? '已置顶' : '已取消置顶')
     // 刷新 PinnedProject 组件的数据