📦 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/@babel/preset-modules/lib/plugins/transform-edge-function-name/index.js

@@ -0,0 +1,42 @@
+"use strict";
+
+exports.__esModule = true;
+exports.default = void 0;
+
+/**
+ * Edge 16 & 17 do not infer function.name from variable assignment.
+ * All other `function.name` behavior works fine, so we can skip most of @babel/transform-function-name.
+ * @see https://kangax.github.io/compat-table/es6/#test-function_name_property_variables_(function)
+ *
+ * Note: contrary to various Github issues, Edge 16+ *does* correctly infer the name of Arrow Functions.
+ * The variable declarator name inference issue only affects function expressions, so that's all we fix here.
+ *
+ * A Note on Minification: Terser undoes this transform *by default* unless `keep_fnames` is set to true.
+ * There is by design - if Function.name is critical to your application, you must configure
+ * your minifier to preserve function names.
+ */
+var _default = ({
+  types: t
+}) => ({
+  name: "transform-edge-function-name",
+  visitor: {
+    FunctionExpression: {
+      exit(path) {
+        if (!path.node.id && t.isIdentifier(path.parent.id)) {
+          const id = t.cloneNode(path.parent.id);
+          const binding = path.scope.getBinding(id.name); // if the binding gets reassigned anywhere, rename it
+
+          if (binding == null ? void 0 : binding.constantViolations.length) {
+            path.scope.rename(id.name);
+          }
+
+          path.node.id = id;
+        }
+      }
+
+    }
+  }
+});
+
+exports.default = _default;
+module.exports = exports.default;