📦 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/thunky/package.json

@@ -0,0 +1,32 @@
+{
+  "name": "thunky",
+  "version": "1.1.0",
+  "description": "delay the evaluation of a paramless async function and cache the result",
+  "main": "index.js",
+  "devDependencies": {
+    "standard": "^12.0.1",
+    "tape": "^4.9.1"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git://github.com/mafintosh/thunky.git"
+  },
+  "scripts": {
+    "test": "standard && tape test.js"
+  },
+  "keywords": [
+    "memo",
+    "thunk",
+    "async",
+    "lazy",
+    "control",
+    "flow",
+    "cache"
+  ],
+  "author": "Mathias Buus Madsen <mathiasbuus@gmail.com>",
+  "bugs": {
+    "url": "https://github.com/mafintosh/thunky/issues"
+  },
+  "homepage": "https://github.com/mafintosh/thunky#readme",
+  "license": "MIT"
+}