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/PinnedProject.vue

@@ -48,7 +48,7 @@
 
 <script setup lang="ts">
 import { ref, onMounted } from 'vue'
-import axios from 'axios'
+import api from '../utils/api'
 import { ElMessage } from 'element-plus'
 import { Loading, InfoFilled, Paperclip } from '@element-plus/icons-vue'
 
@@ -63,7 +63,7 @@ const pinnedLoading = ref(false)
 const loadPinnedBids = async () => {
   pinnedLoading.value = true
   try {
-    const response = await axios.get('/api/bids/pinned')
+    const response = await api.get('/api/bids/pinned')
     pinnedBids.value = response.data
   } catch (error) {
     console.error('Failed to load pinned bids:', error)
@@ -75,7 +75,7 @@ const loadPinnedBids = async () => {
 // 切换置顶列表的 Pin 状态
 const togglePin = async (item: any) => {
   try {
-    await axios.patch(`/api/bids/${encodeURIComponent(item.title)}/pin`, { pin: false })
+    await api.patch(`/api/bids/${encodeURIComponent(item.title)}/pin`, { pin: false })
     const index = pinnedBids.value.findIndex(b => b.title === item.title)
     if (index !== -1) {
       pinnedBids.value.splice(index, 1)