📦 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/tsconfig-paths/lib/match-path-async.d.ts

@@ -0,0 +1,21 @@
+import * as MappingEntry from "./mapping-entry";
+import * as Filesystem from "./filesystem";
+/**
+ * Function that can match a path async
+ */
+export interface MatchPathAsync {
+    (requestedModule: string, readJson: Filesystem.ReadJsonAsync | undefined, fileExists: Filesystem.FileExistsAsync | undefined, extensions: ReadonlyArray<string> | undefined, callback: MatchPathAsyncCallback): void;
+}
+export interface MatchPathAsyncCallback {
+    (err?: Error, path?: string): void;
+}
+/**
+ * See the sync version for docs.
+ */
+export declare function createMatchPathAsync(absoluteBaseUrl: string, paths: {
+    [key: string]: Array<string>;
+}, mainFields?: string[], addMatchAll?: boolean): MatchPathAsync;
+/**
+ * See the sync version for docs.
+ */
+export declare function matchFromAbsolutePathsAsync(absolutePathMappings: ReadonlyArray<MappingEntry.MappingEntry>, requestedModule: string, readJson: Filesystem.ReadJsonAsync | undefined, fileExists: Filesystem.FileExistsAsync | undefined, extensions: readonly string[] | undefined, callback: MatchPathAsyncCallback, mainFields?: string[]): void;