📦 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/pullAllWith.js

@@ -0,0 +1,32 @@
+var basePullAll = require('./_basePullAll');
+
+/**
+ * This method is like `_.pullAll` except that it accepts `comparator` which
+ * is invoked to compare elements of `array` to `values`. The comparator is
+ * invoked with two arguments: (arrVal, othVal).
+ *
+ * **Note:** Unlike `_.differenceWith`, this method mutates `array`.
+ *
+ * @static
+ * @memberOf _
+ * @since 4.6.0
+ * @category Array
+ * @param {Array} array The array to modify.
+ * @param {Array} values The values to remove.
+ * @param {Function} [comparator] The comparator invoked per element.
+ * @returns {Array} Returns `array`.
+ * @example
+ *
+ * var array = [{ 'x': 1, 'y': 2 }, { 'x': 3, 'y': 4 }, { 'x': 5, 'y': 6 }];
+ *
+ * _.pullAllWith(array, [{ 'x': 3, 'y': 4 }], _.isEqual);
+ * console.log(array);
+ * // => [{ 'x': 1, 'y': 2 }, { 'x': 5, 'y': 6 }]
+ */
+function pullAllWith(array, values, comparator) {
+  return (array && array.length && values && values.length)
+    ? basePullAll(array, values, undefined, comparator)
+    : array;
+}
+
+module.exports = pullAllWith;