📦 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-import/docs/rules/no-deprecated.md

@@ -0,0 +1,62 @@
+# import/no-deprecated
+
+<!-- end auto-generated rule header -->
+
+Reports use of a deprecated name, as indicated by a JSDoc block with a `@deprecated`
+tag or TomDoc `Deprecated:` comment.
+
+using a JSDoc `@deprecated` tag:
+
+```js
+// @file: ./answer.js
+
+/**
+ * this is what you get when you trust a mouse talk show
+ * @deprecated need to restart the experiment
+ * @returns {Number} nonsense
+ */
+export function multiply(six, nine) {
+  return 42
+}
+```
+
+will report as such:
+
+```js
+import { multiply } from './answer' // Deprecated: need to restart the experiment
+
+function whatever(y, z) {
+  return multiply(y, z) // Deprecated: need to restart the experiment
+}
+```
+
+or using the TomDoc equivalent:
+
+```js
+// Deprecated: This is what you get when you trust a mouse talk show, need to
+// restart the experiment.
+//
+// Returns a Number nonsense
+export function multiply(six, nine) {
+  return 42
+}
+```
+
+Only JSDoc is enabled by default. Other documentation styles can be enabled with
+the `import/docstyle` setting.
+
+```yaml
+# .eslintrc.yml
+settings:
+  import/docstyle: ['jsdoc', 'tomdoc']
+```
+
+## Worklist
+
+ - [x] report explicit imports on the import node
+ - [x] support namespaces
+   - [x] should bubble up through deep namespaces (#157)
+ - [x] report explicit imports at reference time (at the identifier) similar to namespace
+ - [x] mark module deprecated if file JSDoc has a @deprecated tag?
+ - [ ] don't flag redeclaration of imported, deprecated names
+ - [ ] flag destructuring