📦 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/fork-ts-checker-webpack-plugin/lib/ForkTsCheckerWebpackPluginOptions.d.ts

@@ -0,0 +1,14 @@
+import { TypeScriptReporterOptions } from './typescript-reporter/TypeScriptReporterOptions';
+import { EsLintReporterOptions } from './eslint-reporter/EsLintReporterOptions';
+import { IssueOptions } from './issue/IssueOptions';
+import { FormatterOptions } from './formatter';
+import LoggerOptions from './logger/LoggerOptions';
+interface ForkTsCheckerWebpackPluginOptions {
+    async?: boolean;
+    typescript?: TypeScriptReporterOptions;
+    eslint?: EsLintReporterOptions;
+    formatter?: FormatterOptions;
+    issue?: IssueOptions;
+    logger?: LoggerOptions;
+}
+export { ForkTsCheckerWebpackPluginOptions };