fix: resolve macos bun interop

Use Bun-safe Electron and child_process import patterns for macOS GitHub Actions tests.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

src/main/AryxAppService.ts

@@ -2,7 +2,7 @@ import { EventEmitter } from 'node:events';
 import { rm } from 'node:fs/promises';
 import { basename, dirname } from 'node:path';
 
-import { dialog, shell } from 'electron';
+import electron from 'electron';
 
 import type {
   AgentActivityEvent,
@@ -107,6 +107,8 @@ import {
   validateSessionToolingSelectionIds,
 } from '@main/sessionToolingConfig';
 
+const { dialog, shell } = electron;
+
 type AppServiceEvents = {
   'workspace-updated': [WorkspaceState];
   'session-event': [SessionEventRecord];