📦 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/merge2/package.json

@@ -0,0 +1,43 @@
+{
+  "name": "merge2",
+  "description": "Merge multiple streams into one stream in sequence or parallel.",
+  "authors": [
+    "Yan Qing <admin@zensh.com>"
+  ],
+  "license": "MIT",
+  "version": "1.4.1",
+  "main": "./index.js",
+  "repository": {
+    "type": "git",
+    "url": "git@github.com:teambition/merge2.git"
+  },
+  "homepage": "https://github.com/teambition/merge2",
+  "keywords": [
+    "merge2",
+    "multiple",
+    "sequence",
+    "parallel",
+    "merge",
+    "stream",
+    "merge stream",
+    "sync"
+  ],
+  "engines": {
+    "node": ">= 8"
+  },
+  "dependencies": {},
+  "devDependencies": {
+    "standard": "^14.3.4",
+    "through2": "^3.0.1",
+    "thunks": "^4.9.6",
+    "tman": "^1.10.0",
+    "to-through": "^2.0.0"
+  },
+  "scripts": {
+    "test": "standard && tman"
+  },
+  "files": [
+    "README.md",
+    "index.js"
+  ]
+}