test: 接入覆盖率工具并在 CI 强制 ≥80% 门禁

后端: 加 pytest-cov + [tool.coverage] 配置, pytest --cov-fail-under=80 (基线~88%)。
前端: 加 @vitest/coverage-v8, vitest.config.ts 设 80% 阈值, 新增 test:coverage 脚本 (基线~93%)。
前端覆盖范围限定 lib/** 纯逻辑层; hooks(use*.ts)待 jsdom 测试栈接入后纳入。
CI backend/frontend job 改跑覆盖率门禁命令。CLAUDE.md 同步 DoD 与 Toolchain。

apps/web/package.json

@@ -9,9 +9,11 @@
     "lint": "next lint",
     "typecheck": "tsc --noEmit",
     "test": "vitest run",
+    "test:coverage": "vitest run --coverage",
     "gen:api": "node scripts/gen-api.mjs"
   },
   "dependencies": {
+    "lucide-react": "^1.21.0",
     "next": "15.1.3",
     "openapi-fetch": "^0.13.0",
     "react": "19.0.0",
@@ -21,10 +23,12 @@
     "@types/node": "^22.10.0",
     "@types/react": "19.0.0",
     "@types/react-dom": "19.0.0",
+    "@vitest/coverage-v8": "^2.1.9",
     "autoprefixer": "^10.4.20",
     "eslint": "^9.17.0",
     "eslint-config-next": "15.1.3",
     "openapi-typescript": "^7.5.0",
+    "playwright": "^1.61.1",
     "postcss": "^8.4.49",
     "tailwindcss": "^3.4.17",
     "typescript": "^5.7.2",