feat: 前端 ESLint 规则增强，自动检测 LLM 编码违规

- 启用 TanStack Query flat/recommended（7 条规则）
- 新增 no-console（允许 warn/error）、consistent-type-imports（inline 风格）、no-non-null-assertion 规则
- 新增自定义规则 no-hardcoded-color-in-style，检测 JSX style 中硬编码颜色值
- 将 ESLint 检查集成到 build 命令（tsc -b && eslint . && vite build）
- 修复现有代码中的 lint 违规（import 顺序、type import 风格、unused vars）
- 使用 @typescript-eslint/rule-tester 编写自定义规则集成测试

frontend/package.json

@@ -5,8 +5,9 @@
   "type": "module",
   "scripts": {
     "dev": "vite",
-    "build": "tsc -b && vite build",
+    "build": "tsc -b && eslint . && vite build",
     "lint": "eslint .",
+    "lint:fix": "eslint . --fix",
     "preview": "vite preview",
     "test": "vitest run",
     "test:watch": "vitest",
@@ -34,6 +35,7 @@
     "@types/react": "^19.2.14",
     "@types/react-dom": "^19.2.3",
     "@types/sql.js": "^1.4.11",
+    "@typescript-eslint/rule-tester": "^8.59.0",
     "@vitejs/plugin-react": "^6.0.1",
     "@vitest/coverage-v8": "^3.2.1",
     "eslint": "^9.39.4",