后端功能增强：全局异常处理、API控制器、JSP视图和单元测试

- 添加 GlobalExceptionHandler 全局异常处理
- 添加 ApiController REST API 控制器
- 更新 WebConfig 跨域配置和 ProductRepository 查询方法
- 新增 monitor/product-detail/profile JSP 视图页面
- 添加 FlashSaleServiceTest 秒杀服务单元测试
- 更新 application.yml 配置

flash-sale-frontend/tsconfig.json

@@ -0,0 +1,26 @@
+{
+  "compilerOptions": {
+    "target": "ES2020",
+    "useDefineForClassFields": true,
+    "module": "ESNext",
+    "lib": ["ES2020", "DOM", "DOM.Iterable"],
+    "skipLibCheck": true,
+    "moduleResolution": "bundler",
+    "allowImportingTsExtensions": true,
+    "resolveJsonModule": true,
+    "isolatedModules": true,
+    "noEmit": true,
+    "jsx": "preserve",
+    "strict": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "noFallthroughCasesInSwitch": true,
+    "baseUrl": ".",
+    "paths": {
+      "@/*": ["src/*"]
+    },
+    "types": ["vite/client", "element-plus/global", "node"]
+  },
+  "include": ["src/**/*.ts", "src/**/*.d.ts", "src/**/*.tsx", "src/**/*.vue"],
+  "references": [{ "path": "./tsconfig.node.json" }]
+}