feat: add Tool Search domain restriction bypass with active-installation patching

Resolve the active `claude` command from PATH and apply an equal-length
byte patch to remove the domain whitelist check. Backups are stored in
~/.cc-switch/toolsearch-backups/ (SHA-256 of path) so they survive
Claude Code version upgrades. The patch auto-reapplies on app startup
when the setting is enabled.

Frontend checks PatchResult.success and rolls back the setting on failure.

src/types.ts

@@ -226,6 +226,8 @@ export interface Settings {
   enableClaudePluginIntegration?: boolean;
   // 跳过 Claude Code 初次安装确认（写入 ~/.claude.json 的 hasCompletedOnboarding）
   skipClaudeOnboarding?: boolean;
+  // 解除 Tool Search 域名限制
+  toolSearchBypass?: boolean;
   // 是否开机自启
   launchOnStartup?: boolean;
   // 静默启动（程序启动时不显示主窗口）