📦 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-jsx-a11y/docs/rules/scope.md

@@ -0,0 +1,30 @@
+# jsx-a11y/scope
+
+💼 This rule is enabled in the following configs: ☑️ `recommended`, 🔒 `strict`.
+
+<!-- end auto-generated rule header -->
+
+The `scope` prop should be used only on `<th>` elements.
+
+## Rule details
+
+This rule takes no arguments.
+
+### Succeed
+```jsx
+<th scope="col" />
+<th scope={scope} />
+```
+
+### Fail
+
+```jsx
+<div scope />
+```
+
+## Accessibility guidelines
+- [WCAG 1.3.1](https://www.w3.org/WAI/WCAG21/Understanding/info-and-relationships)
+- [WCAG 4.1.1](https://www.w3.org/WAI/WCAG21/Understanding/parsing)
+
+### Resources
+- [axe-core, scope-attr-valid](https://dequeuniversity.com/rules/axe/3.5/scope-attr-valid)