📦 添加虚拟环境和启动脚本

新增:
- backend/venv/ - Python 虚拟环境
- backend/start.sh - 启动脚本（使用虚拟环境）
- backend/requirements.txt - 依赖列表
- .gitignore - 忽略虚拟环境和缓存文件

说明:
- 每个项目使用独立虚拟环境
- 避免依赖冲突
- 启动脚本自动创建和激活虚拟环境

frontend/node_modules/eslint-plugin-react-hooks/README.md

@@ -0,0 +1,75 @@
+# `eslint-plugin-react-hooks`
+
+This ESLint plugin enforces the [Rules of Hooks](https://reactjs.org/docs/hooks-rules.html).
+
+It is a part of the [Hooks API](https://reactjs.org/docs/hooks-intro.html) for React.
+
+## Installation
+
+**Note: If you're using Create React App, please use `react-scripts` >= 3 instead of adding it directly.**
+
+Assuming you already have ESLint installed, run:
+
+```sh
+# npm
+npm install eslint-plugin-react-hooks --save-dev
+
+# yarn
+yarn add eslint-plugin-react-hooks --dev
+```
+
+Then extend the recommended eslint config:
+
+```js
+{
+  "extends": [
+    // ...
+    "plugin:react-hooks/recommended"
+  ]
+}
+```
+
+### Custom Configuration
+
+If you want more fine-grained configuration, you can instead add a snippet like this to your ESLint configuration file:
+
+```js
+{
+  "plugins": [
+    // ...
+    "react-hooks"
+  ],
+  "rules": {
+    // ...
+    "react-hooks/rules-of-hooks": "error",
+    "react-hooks/exhaustive-deps": "warn"
+  }
+}
+```
+
+
+## Advanced Configuration
+
+`exhaustive-deps` can be configured to validate dependencies of custom Hooks with the `additionalHooks` option.
+This option accepts a regex to match the names of custom Hooks that have dependencies.
+
+```js
+{
+  "rules": {
+    // ...
+    "react-hooks/exhaustive-deps": ["warn", {
+      "additionalHooks": "(useMyCustomHook|useMyOtherCustomHook)"
+    }]
+  }
+}
+```
+
+We suggest to use this option **very sparingly, if at all**. Generally saying, we recommend most custom Hooks to not use the dependencies argument, and instead provide a higher-level API that is more focused around a specific use case.
+
+## Valid and Invalid Examples
+
+Please refer to the [Rules of Hooks](https://reactjs.org/docs/hooks-rules.html) documentation and the [Hooks FAQ](https://reactjs.org/docs/hooks-faq.html#what-exactly-do-the-lint-rules-enforce) to learn more about this rule.
+
+## License
+
+MIT