diff --git a/frontend/package.json b/frontend/package.json
index 1378c94..e62840a 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -1,33 +1,35 @@
-{
-  "name": "frontend",
-  "version": "1.0.0",
-  "description": "",
-  "main": "index.js",
-  "scripts": {
-    "dev": "vite",
-    "build": "vite build",
-    "preview": "vite preview"
-  },
-  "keywords": [],
-  "author": "",
-  "license": "ISC",
-  "dependencies": {
-    "@types/qrcode": "^1.5.6",
-    "highlight.js": "^11.11.1",
-    "html2canvas": "^1.4.1",
-    "jspdf": "^4.2.1",
-    "katex": "^0.17.0",
-    "mermaid": "^11.16.0",
-    "qrcode": "^1.5.4",
-    "react": "^18.3.1",
-    "react-dom": "^18.3.1",
-    "react-router-dom": "^6.30.3"
-  },
-  "devDependencies": {
-    "@types/react": "^18.3.29",
-    "@types/react-dom": "^18.3.7",
-    "@vitejs/plugin-react": "^4.7.0",
-    "typescript": "^5.9.3",
-    "vite": "^5.4.21"
-  }
-}
+{
+  "name": "frontend",
+  "version": "1.0.0",
+  "description": "",
+  "main": "index.js",
+  "scripts": {
+    "dev": "vite",
+    "build": "vite build",
+    "preview": "vite preview",
+    "test": "vitest run"
+  },
+  "keywords": [],
+  "author": "",
+  "license": "ISC",
+  "dependencies": {
+    "@types/qrcode": "^1.5.6",
+    "highlight.js": "^11.11.1",
+    "html2canvas": "^1.4.1",
+    "jspdf": "^4.2.1",
+    "katex": "^0.17.0",
+    "mermaid": "^11.16.0",
+    "qrcode": "^1.5.4",
+    "react": "^18.3.1",
+    "react-dom": "^18.3.1",
+    "react-router-dom": "^6.30.3"
+  },
+  "devDependencies": {
+    "@types/react": "^18.3.29",
+    "@types/react-dom": "^18.3.7",
+    "@vitejs/plugin-react": "^4.7.0",
+    "typescript": "^5.9.3",
+    "vite": "^5.4.21",
+    "vitest": "^4.1.10"
+  }
+}
diff --git a/frontend/src/utils/datetime.test.ts b/frontend/src/utils/datetime.test.ts
new file mode 100644
index 0000000..05db8d3
--- /dev/null
+++ b/frontend/src/utils/datetime.test.ts
@@ -0,0 +1,29 @@
+import { describe, it, expect } from 'vitest';
+import { formatBjTime } from './datetime';
+
+// 北京时间渲染曾是反复出现的问题（微信Bot时间错乱、Token驾驶舱时间列不正确等）。
+// 该测试固化「后端按北京时间存储、前端显式按 Asia/Shanghai 渲染」的契约。
+describe('formatBjTime', () => {
+  it('空输入返回占位符 -', () => {
+    expect(formatBjTime(undefined)).toBe('-');
+    expect(formatBjTime(null)).toBe('-');
+    expect(formatBjTime('')).toBe('-');
+  });
+
+  it('无时区标记的时间戳按 Asia/Shanghai (+08:00) 渲染', () => {
+    // 2026-07-18T12:00:00 视为北京时间，渲染应含 12:00:00
+    const out = formatBjTime('2026-07-18T12:00:00');
+    expect(out).toContain('2026');
+    expect(out).toContain('12:00:00');
+  });
+
+  it('UTC(Z) 时间戳正确转换为北京时间 (+8)', () => {
+    // 2026-07-18T04:00:00Z = 北京时间 12:00:00
+    const out = formatBjTime('2026-07-18T04:00:00Z');
+    expect(out).toContain('12:00:00');
+  });
+
+  it('非法日期原样返回', () => {
+    expect(formatBjTime('not-a-date')).toBe('not-a-date');
+  });
+});
diff --git a/frontend/vite.config.ts b/frontend/vite.config.ts
index 6e583cc..d1d4947 100644
--- a/frontend/vite.config.ts
+++ b/frontend/vite.config.ts
@@ -1,4 +1,5 @@
-import { defineConfig } from 'vite';
+/// <reference types="vitest/config" />
+import { defineConfig } from 'vitest/config';
 import react from '@vitejs/plugin-react';
 import path from 'path';
 
@@ -17,8 +18,6 @@ export default defineConfig({
     chunkSizeWarningLimit: 1200,
     rollupOptions: {
       output: {
-        // 仅将 react 核心库单独打包（长期缓存）；
-        // 其余第三方库交给 Rollup 自动按需拆分，避免被强制合并成一个大 vendor 在首屏加载
         manualChunks(id) {
           if (id.includes('node_modules')) {
             if (
@@ -37,4 +36,9 @@ export default defineConfig({
   server: {
     port: 5173,
   },
+  // Phase 0 测试基建：vitest 配置（纯函数测试用 node 环境，组件测试可改 jsdom）
+  test: {
+    environment: 'node',
+    include: ['src/**/*.test.ts'],
+  },
 });