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/lib/api/settings.ts

@@ -86,6 +86,18 @@ export const settingsApi = {
     return await invoke("clear_claude_onboarding_skip");
   },
 
+  async applyToolSearchPatch(): Promise<
+    Array<{ path: string; success: boolean; error?: string }>
+  > {
+    return await invoke("apply_toolsearch_patch");
+  },
+
+  async restoreToolSearchPatch(): Promise<
+    Array<{ path: string; success: boolean; error?: string }>
+  > {
+    return await invoke("restore_toolsearch_patch");
+  },
+
   async saveFileDialog(defaultName: string): Promise<string | null> {
     return await invoke("save_file_dialog", { defaultName });
   },