feat: 新增可配置的路径前缀以支持子路径部署

添加前后端环境变量配置示例，新增后端路径前缀配置项，更新后端路由与静态文件挂载逻辑，调整前端代理配置与 API 调用代码，适配子路径部署场景。

frontend/vite.config.ts

@@ -1,40 +1,46 @@
-import { defineConfig } from 'vite'
+import { defineConfig, loadEnv } from 'vite'
 import path from 'path'
 import tailwindcss from '@tailwindcss/vite'
 import react from '@vitejs/plugin-react'
 import basicSsl from '@vitejs/plugin-basic-ssl'
 
-export default defineConfig({
-  base: '/app_03/',
-  plugins: [
-    // The React and Tailwind plugins are both required for Make, even if
-    // Tailwind is not being actively used – do not remove them
-    react(),
-    tailwindcss(),
-    // basicSsl(), // disabled for cloudflare tunnel compatibility
-  ],
-  resolve: {
-    alias: {
-      // Alias @ to the src directory
-      '@': path.resolve(__dirname, './src'),
-    },
-  },
+export default defineConfig(({ mode }) => {
+  const env = loadEnv(mode, process.cwd(), '')
+  const apiPrefix = env.VITE_API_PREFIX || '/api'
+  const uploadsPrefix = env.VITE_UPLOADS_PREFIX || '/uploads'
 
-  // File types to support raw imports. Never add .css, .tsx, or .ts files to this.
-  assetsInclude: ['**/*.svg', '**/*.csv'],
-
-  server: {
-    host: '0.0.0.0',
-    allowedHosts: ['.trycloudflare.com', '.loca.lt'],
-    proxy: {
-      '/api': {
-        target: 'http://localhost:8000',
-        changeOrigin: true,
-      },
-      '/uploads': {
-        target: 'http://localhost:8000',
-        changeOrigin: true,
+  return {
+    base: '/app_03/',
+    plugins: [
+      // The React and Tailwind plugins are both required for Make, even if
+      // Tailwind is not being actively used – do not remove them
+      react(),
+      tailwindcss(),
+      // basicSsl(), // disabled for cloudflare tunnel compatibility
+    ],
+    resolve: {
+      alias: {
+        // Alias @ to the src directory
+        '@': path.resolve(__dirname, './src'),
       },
     },
-  },
+
+    // File types to support raw imports. Never add .css, .tsx, or .ts files to this.
+    assetsInclude: ['**/*.svg', '**/*.csv'],
+
+    server: {
+      host: '0.0.0.0',
+      allowedHosts: ['.trycloudflare.com', '.loca.lt'],
+      proxy: {
+        [apiPrefix]: {
+          target: 'http://localhost:8000',
+          changeOrigin: true,
+        },
+        [uploadsPrefix]: {
+          target: 'http://localhost:8000',
+          changeOrigin: true,
+        },
+      },
+    },
+  }
 })