feat(web): add frontend scaffold with React 19 and TanStack Router

- Initialize Vite + React 19 + TypeScript project
- Add TanStack Router v1.95 with file-based routing
- Add TanStack Query v5.64 for data fetching
- Configure Tailwind CSS + shadcn/ui
- Implement auth features (useAuth hook, LoginButton, AuthGuard)
- Add openapi-fetch client for type-safe API calls
- Configure Nginx for production deployment
- Update Makefile with frontend commands

Implements Task 3 (Chunk 3) of Phase 1 plan.

Makefile

@@ -24,6 +24,27 @@ clean:
 	cd server && ./mvnw clean
 	docker compose down -v
 
-# 生成 OpenAPI 类型（前端用，Phase 1 暂不实现）
+# 生成 OpenAPI 类型（前端用）
 generate-api:
-	@echo "Frontend not yet implemented"
+	@echo "Generating OpenAPI types..."
+	cd web && pnpm run generate-api
+
+# 前端开发服务器
+dev-web:
+	cd web && pnpm run dev
+
+# 构建前端
+build-web:
+	cd web && pnpm run build
+
+# 前端测试
+test-web:
+	cd web && pnpm run test
+
+# 前端类型检查
+typecheck-web:
+	cd web && pnpm run typecheck
+
+# 前端代码检查
+lint-web:
+	cd web && pnpm run lint