📦 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-anonymous-default-export.md

@@ -0,0 +1,83 @@
+# import/no-anonymous-default-export
+
+<!-- end auto-generated rule header -->
+
+Reports if a module's default export is unnamed. This includes several types of unnamed data types; literals, object expressions, arrays, anonymous functions, arrow functions, and anonymous class declarations.
+
+Ensuring that default exports are named helps improve the grepability of the codebase by encouraging the re-use of the same identifier for the module's default export at its declaration site and at its import sites.
+
+## Options
+
+By default, all types of anonymous default exports are forbidden, but any types can be selectively allowed by toggling them on in the options.
+
+The complete default configuration looks like this.
+
+```js
+"import/no-anonymous-default-export": ["error", {
+  "allowArray": false,
+  "allowArrowFunction": false,
+  "allowAnonymousClass": false,
+  "allowAnonymousFunction": false,
+  "allowCallExpression": true, // The true value here is for backward compatibility
+  "allowNew": false,
+  "allowLiteral": false,
+  "allowObject": false
+}]
+```
+
+## Rule Details
+
+### Fail
+
+```js
+export default []
+
+export default () => {}
+
+export default class {}
+
+export default function () {}
+
+/* eslint import/no-anonymous-default-export: [2, {"allowCallExpression": false}] */
+export default foo(bar)
+
+export default 123
+
+export default {}
+
+export default new Foo()
+```
+
+### Pass
+
+```js
+const foo = 123
+export default foo
+
+export default class MyClass() {}
+
+export default function foo() {}
+
+/* eslint import/no-anonymous-default-export: [2, {"allowArray": true}] */
+export default []
+
+/* eslint import/no-anonymous-default-export: [2, {"allowArrowFunction": true}] */
+export default () => {}
+
+/* eslint import/no-anonymous-default-export: [2, {"allowAnonymousClass": true}] */
+export default class {}
+
+/* eslint import/no-anonymous-default-export: [2, {"allowAnonymousFunction": true}] */
+export default function () {}
+
+export default foo(bar)
+
+/* eslint import/no-anonymous-default-export: [2, {"allowLiteral": true}] */
+export default 123
+
+/* eslint import/no-anonymous-default-export: [2, {"allowObject": true}] */
+export default {}
+
+/* eslint import/no-anonymous-default-export: [2, {"allowNew": true}] */
+export default new Foo()
+```