📦 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/lodash/unzipWith.js

@@ -0,0 +1,39 @@
+var apply = require('./_apply'),
+    arrayMap = require('./_arrayMap'),
+    unzip = require('./unzip');
+
+/**
+ * This method is like `_.unzip` except that it accepts `iteratee` to specify
+ * how regrouped values should be combined. The iteratee is invoked with the
+ * elements of each group: (...group).
+ *
+ * @static
+ * @memberOf _
+ * @since 3.8.0
+ * @category Array
+ * @param {Array} array The array of grouped elements to process.
+ * @param {Function} [iteratee=_.identity] The function to combine
+ *  regrouped values.
+ * @returns {Array} Returns the new array of regrouped elements.
+ * @example
+ *
+ * var zipped = _.zip([1, 2], [10, 20], [100, 200]);
+ * // => [[1, 10, 100], [2, 20, 200]]
+ *
+ * _.unzipWith(zipped, _.add);
+ * // => [3, 30, 300]
+ */
+function unzipWith(array, iteratee) {
+  if (!(array && array.length)) {
+    return [];
+  }
+  var result = unzip(array);
+  if (iteratee == null) {
+    return result;
+  }
+  return arrayMap(result, function(group) {
+    return apply(iteratee, undefined, group);
+  });
+}
+
+module.exports = unzipWith;