📦 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/webpack/lib/dependencies/ModuleDependencyTemplateAsId.js

@@ -0,0 +1,35 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+
+"use strict";
+
+const ModuleDependency = require("./ModuleDependency");
+
+/** @typedef {import("webpack-sources").ReplaceSource} ReplaceSource */
+/** @typedef {import("../Dependency")} Dependency */
+/** @typedef {import("../DependencyTemplate").DependencyTemplateContext} DependencyTemplateContext */
+/** @typedef {import("../Module")} Module */
+
+class ModuleDependencyTemplateAsId extends ModuleDependency.Template {
+	/**
+	 * @param {Dependency} dependency the dependency for which the template should be applied
+	 * @param {ReplaceSource} source the current replace source which can be modified
+	 * @param {DependencyTemplateContext} templateContext the context object
+	 * @returns {void}
+	 */
+	apply(dependency, source, { runtimeTemplate, moduleGraph, chunkGraph }) {
+		const dep = /** @type {ModuleDependency} */ (dependency);
+		if (!dep.range) return;
+		const content = runtimeTemplate.moduleId({
+			module: /** @type {Module} */ (moduleGraph.getModule(dep)),
+			chunkGraph,
+			request: dep.request,
+			weak: dep.weak
+		});
+		source.replace(dep.range[0], dep.range[1] - 1, content);
+	}
+}
+
+module.exports = ModuleDependencyTemplateAsId;