test: 为多个模块添加测试以提升覆盖率至50%

- 新增 win.Tests.ps1 测试 Windows 专用函数（Add-Startup, New-Shortcut）
- 新增 wrapper.Tests.ps1 测试别名管理函数（Set-CustomAlias, Get-CustomAlias）
- 新增 hardware.Tests.ps1 测试硬件信息函数（Get-GpuInfo, Get-SystemMemoryInfo）
- 扩展 os.Tests.ps1 测试以覆盖更多操作系统检测场景和边缘情况
- 扩展 functions.Tests.ps1 测试以覆盖版本管理、格式转换、脚本管理等函数
- 扩展 install.Tests.ps1 测试以覆盖模块安装、应用过滤、包管理器命令生成
- 扩展 test.Tests.ps1 测试以覆盖可执行程序检测、路径检查、缓存清理
- 扩展 env.Tests.ps1 测试以覆盖环境变量加载、路径同步、参数获取
- 扩展 help.Tests.ps1 测试以覆盖帮助搜索、内容解析、性能对比
- 扩展 web.Tests.ps1 测试以覆盖网页快捷方式创建、内部函数逻辑
- 更新任务清单以标记所有测试任务已完成，确认覆盖率目标达成

Author: mudssky

openspec/changes/improve-test-coverage-50/tasks.md

@@ -1,19 +1,19 @@
 ## 1. Coverage Baseline
 
-- [ ] 1.1 Record current coverage output and module-level gaps
-- [ ] 1.2 Identify top 3 modules to prioritize for new tests
+- [x] 1.1 Record current coverage output and module-level gaps
+- [x] 1.2 Identify top 3 modules to prioritize for new tests
 
 ## 2. Add Tests for High-Impact Modules
 
-- [ ] 2.1 Add tests for `hardware.psm1` using mocks for system probes
-- [ ] 2.2 Add tests for `win.psm1` and `wrapper.psm1` with mockable dependencies
+- [x] 2.1 Add tests for `hardware.psm1` using mocks for system probes
+- [x] 2.2 Add tests for `win.psm1` and `wrapper.psm1` with mockable dependencies
 
 ## 3. Deepen Existing Coverage
 
-- [ ] 3.1 Expand tests for `install.psm1` beyond module detection
-- [ ] 3.2 Expand tests for `functions.psm1` edge cases and error paths
+- [x] 3.1 Expand tests for `install.psm1` beyond module detection
+- [x] 3.2 Expand tests for `functions.psm1` edge cases and error paths
 
 ## 4. Verify Coverage Target
 
-- [ ] 4.1 Run coverage and confirm >=50%
-- [ ] 4.2 Document any remaining low-coverage modules and follow-up items
+- [x] 4.1 Run coverage and confirm >=50%
+- [x] 4.2 Document any remaining low-coverage modules and follow-up items