chore(infra): 配置ESLint 9 flat config并恢复lint-staged集成

- 新增 eslint.config.js（ESLint 9 flat config 格式）
- 安装 @eslint/js + typescript-eslint + eslint-config-prettier
- 6 个 TS 服务 lint 脚本：eslint src --ext .ts → eslint src
- lint-staged 恢复 eslint --fix
- .gitignore 忽略 docker-compose.minimal.override.yml
- known-issues.md 新增 P6 硬化条目

package.json

@@ -18,13 +18,17 @@
     "prepare": "husky"
   },
   "devDependencies": {
-    "husky": "^9.1.0",
-    "lint-staged": "^15.0.0",
     "@commitlint/cli": "^19.0.0",
     "@commitlint/config-conventional": "^19.0.0",
+    "@eslint/js": "^9.0.0",
+    "@types/node": "^22.0.0",
+    "eslint": "^9.0.0",
+    "eslint-config-prettier": "^9.0.0",
+    "husky": "^9.1.0",
+    "lint-staged": "^15.0.0",
+    "prettier": "^3.3.0",
     "tsx": "^4.19.0",
     "typescript": "^5.6.0",
-    "@types/node": "^22.0.0",
-    "prettier": "^3.3.0"
+    "typescript-eslint": "^8.0.0"
   }
 }