feat: frontend 架构基座（横切层 + 接通 tailwind）

- 横切层：utils/logger（统一日志，禁 console.log）、services/wsClient（通用 WS 客户端）、
  components/ErrorBoundary（错误边界）；main.tsx 接 ErrorBoundary + Toaster
- 接通 tailwind：补 tailwind.config.js + postcss.config.js + @tailwind 指令
  （此前 tailwindcss/postcss/autoprefixer 是悬空依赖，无配置）
- vite-env.d.ts：VITE_ 环境变量类型（按 include_backend 渲染）
- App.tsx 改用 tailwind utility class（规则禁自定义 CSS）
- 验证：build/lint/typecheck 三门禁全过

至此三服务架构基座完成：copier 预生成横切层，每个生成项目第一天即结构完整、能跑、过门禁。

template/frontend/postcss.config.js

@@ -0,0 +1,6 @@
+export default {
+  plugins: {
+    tailwindcss: {},
+    autoprefixer: {},
+  },
+};

template/frontend/src/App.tsx.jinja

@@ -1,8 +1,11 @@
 export default function App() {
   return (
-    <main>
-      <h1>{{ project_name }}</h1>
-      <p>脚手架已就绪。按 <code>.claude/rules</code> 在 <code>src/</code> 下分层实现业务。</p>
+    <main className="mx-auto max-w-2xl p-8">
+      <h1 className="text-2xl font-bold">{{ project_name }}</h1>
+      <p className="mt-2 text-gray-600">
+        脚手架已就绪。按 <code className="rounded bg-gray-100 px-1">.claude/rules</code>
+        {" "}在 <code className="rounded bg-gray-100 px-1">src/</code> 下分层实现业务。
+      </p>
     </main>
   );
 }

template/frontend/src/components/ErrorBoundary.tsx

@@ -0,0 +1,26 @@
+import { Component, type ErrorInfo, type ReactNode } from "react";
+
+import { logger } from "../utils/logger";
+
+type Props = { children: ReactNode };
+type State = { hasError: boolean };
+
+// 组件级错误边界：捕获渲染异常，记录日志并展示兜底 UI。
+export class ErrorBoundary extends Component<Props, State> {
+  state: State = { hasError: false };
+
+  static getDerivedStateFromError(): State {
+    return { hasError: true };
+  }
+
+  componentDidCatch(error: Error, info: ErrorInfo): void {
+    logger.error("component error", { message: error.message, info });
+  }
+
+  render(): ReactNode {
+    if (this.state.hasError) {
+      return <div className="p-8 text-red-600">页面出错了，请刷新重试。</div>;
+    }
+    return this.props.children;
+  }
+}

template/frontend/src/index.css

@@ -1,17 +1,3 @@
-:root {
-  font-family: system-ui, -apple-system, sans-serif;
-  line-height: 1.5;
-  color: #1a1a1a;
-}
-
-body {
-  margin: 0;
-  padding: 2rem;
-}
-
-code {
-  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
-  background: #f0f0f0;
-  padding: 0.1em 0.3em;
-  border-radius: 3px;
-}
+@tailwind base;
+@tailwind components;
+@tailwind utilities;

template/frontend/src/main.tsx

@@ -1,7 +1,9 @@
 import { StrictMode } from "react";
 import { createRoot } from "react-dom/client";
+import { Toaster } from "sonner";
 
 import App from "./App";
+import { ErrorBoundary } from "./components/ErrorBoundary";
 import "./index.css";
 
 const root = document.getElementById("root");
@@ -9,6 +11,9 @@ if (!root) throw new Error("root element not found");
 
 createRoot(root).render(
   <StrictMode>
+    <ErrorBoundary>
       <App />
+      <Toaster />
+    </ErrorBoundary>
   </StrictMode>,
 );

template/frontend/src/services/wsClient.ts

@@ -0,0 +1,33 @@
+import { logger } from "../utils/logger";
+
+export type WsHandlers = {
+  onMessage: (data: unknown) => void;
+  onOpen?: () => void;
+  onClose?: () => void;
+};
+
+// 通用 WebSocket 客户端：建连 + 收发 + 消息反序列化。
+// 业务层在 hooks 中调用，组件不直接碰（见 .claude/rules/frontend.md 分层边界）。
+export function connectWs(url: string, handlers: WsHandlers): WebSocket {
+  const ws = new WebSocket(url);
+  ws.onopen = (): void => {
+    logger.info("ws open", { url });
+    handlers.onOpen?.();
+  };
+  ws.onmessage = (e: MessageEvent): void => {
+    try {
+      handlers.onMessage(JSON.parse(e.data));
+    } catch (err) {
+      logger.warn("invalid ws message", { err });
+    }
+  };
+  ws.onclose = (): void => {
+    logger.info("ws closed");
+    handlers.onClose?.();
+  };
+  return ws;
+}
+
+export function sendWs(ws: WebSocket, message: object): void {
+  ws.send(JSON.stringify(message));
+}

template/frontend/src/utils/logger.ts

@@ -0,0 +1,14 @@
+// 统一前端日志：dev 输出 console，prod 可接 Sentry。
+// 禁止在组件/hooks 直接用 console.log（见 .claude/rules/frontend-runtime.md）。
+export const logger = {
+  info: (msg: string, ctx?: object): void => {
+    // eslint-disable-next-line no-console
+    if (import.meta.env.DEV) console.info(`[INFO] ${msg}`, ctx ?? "");
+  },
+  warn: (msg: string, ctx?: object): void => {
+    console.warn(`[WARN] ${msg}`, ctx ?? "");
+  },
+  error: (msg: string, ctx?: object): void => {
+    console.error(`[ERROR] ${msg}`, ctx ?? "");
+  },
+};

template/frontend/src/vite-env.d.ts.jinja

@@ -0,0 +1,12 @@
+/// <reference types="vite/client" />
+
+interface ImportMetaEnv {
+{%- if include_backend %}
+  readonly VITE_BACKEND_WS_URL: string;
+  readonly VITE_BACKEND_HTTP_URL: string;
+{%- endif %}
+}
+
+interface ImportMeta {
+  readonly env: ImportMetaEnv;
+}

template/frontend/tailwind.config.js

@@ -0,0 +1,6 @@
+/** @type {import('tailwindcss').Config} */
+export default {
+  content: ["./index.html", "./src/**/*.{ts,tsx}"],
+  theme: { extend: {} },
+  plugins: [],
+};