chore(quality): 接入 ESLint 与 GitLab CI,开启严格未用检查,构建期设计令牌守卫

- eslint.config.mjs(flat config):react-hooks/react-refresh/tseslint;自定义 no-restricted-syntax
  规则禁止 className 手拼基元类名(error 级,JSXAttribute 选择器精确限定,探针双向验证)与硬编码色值
- tsconfig:noUnusedLocals/noUnusedParameters 置 true
- package.json 新增 typecheck/lint/test/verify:tokens 脚本;build 串联令牌校验(verify-tokens.sh
  防止 <alpha-value> 类静默失效回归);pnpm-lock.yaml 入库供 CI --frozen-lockfile
- .gitlab-ci.yml:lint/typecheck/test/build 四作业,MR 与默认分支触发,dist 产物留存一周

frontend/tsconfig.json

@@ -12,8 +12,8 @@
     "noEmit": true,
     "jsx": "react-jsx",
     "strict": true,
-    "noUnusedLocals": false,
-    "noUnusedParameters": false,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
     "noFallthroughCasesInSwitch": true
   },
   "include": ["src"],