Initial commit: Text Adventure Game

Features:
- Combat system with AP/EP hit calculation and three-layer defense
- Auto-combat/farming mode
- Item system with stacking support
- Skill system with levels, milestones, and parent skill sync
- Shop system with dynamic pricing
- Inventory management with bulk selling
- Event system
- Game loop with offline earnings
- Save/Load system

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

tests/helpers/random.js

@@ -0,0 +1,74 @@
+/**
+ * 随机数测试辅助函数
+ */
+
+import { vi } from 'vitest'
+
+let mockRandomValue = 0.5
+
+/**
+ * 设置 Math.random() 返回值
+ * @param {number} value - 返回值（0-1）
+ */
+export function setMockRandom(value) {
+  mockRandomValue = value
+}
+
+/**
+ * 创建 Math.random() 的 mock
+ * @returns {Object} spy
+ */
+export function mockMathRandom() {
+  return vi.spyOn(Math, 'random').mockImplementation(() => mockRandomValue)
+}
+
+/**
+ * 重置 mock 随机值
+ */
+export function resetMockRandom() {
+  mockRandomValue = 0.5
+}
+
+/**
+ * 设置随机数序列
+ * @param {Array<number>} values - 随机数序列
+ * @returns {Object} spy
+ */
+export function mockRandomSequence(values) {
+  let index = 0
+  return vi.spyOn(Math, 'random').mockImplementation(() => {
+    const value = values[index % values.length]
+    index++
+    return value
+  })
+}
+
+/**
+ * 创建确定性的随机数生成器
+ * @param {number} seed - 种子值
+ * @returns {Function} 随机函数
+ */
+export function createSeededRandom(seed) {
+  return () => {
+    seed = (seed * 9301 + 49297) % 233280
+    return seed / 233280
+  }
+}
+
+/**
+ * Mock 随机数生成器
+ * @param {number} seed - 种子值
+ * @returns {Object} spy
+ */
+export function mockSeededRandom(seed) {
+  const randomFunc = createSeededRandom(seed)
+  return vi.spyOn(Math, 'random').mockImplementation(randomFunc)
+}
+
+/**
+ * 清理所有 mock
+ */
+export function cleanupMocks() {
+  vi.restoreAllMocks()
+  resetMockRandom()
+}