📦 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/container/ContainerEntryDependency.js

@@ -0,0 +1,50 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra, Zackary Jackson @ScriptedAlchemy, Marais Rossouw @maraisr
+*/
+
+"use strict";
+
+const Dependency = require("../Dependency");
+const makeSerializable = require("../util/makeSerializable");
+
+/** @typedef {import("./ContainerEntryModule").ExposesList} ExposesList */
+
+class ContainerEntryDependency extends Dependency {
+	/**
+	 * @param {string} name entry name
+	 * @param {ExposesList} exposes list of exposed modules
+	 * @param {string} shareScope name of the share scope
+	 */
+	constructor(name, exposes, shareScope) {
+		super();
+		/** @type {string} */
+		this.name = name;
+		/** @type {ExposesList} */
+		this.exposes = exposes;
+		/** @type {string} */
+		this.shareScope = shareScope;
+	}
+
+	/**
+	 * @returns {string | null} an identifier to merge equal requests
+	 */
+	getResourceIdentifier() {
+		return `container-entry-${this.name}`;
+	}
+
+	get type() {
+		return "container entry";
+	}
+
+	get category() {
+		return "esm";
+	}
+}
+
+makeSerializable(
+	ContainerEntryDependency,
+	"webpack/lib/container/ContainerEntryDependency"
+);
+
+module.exports = ContainerEntryDependency;