fix: close and recreate macOS windows safely

electron/main/ipc/transcript-export.ts

@@ -1,5 +1,6 @@
 import { writeFile } from 'node:fs/promises';
-import { dialog, ipcMain, type BrowserWindow } from 'electron';
+import { BrowserWindow, dialog, ipcMain } from 'electron';
+import { resolveMainWindow, type MainWindowProvider } from '../window-provider';
 
 interface TranscriptSaveRequest {
   defaultPath?: unknown;
@@ -15,8 +16,8 @@ function safeDefaultPath(value: unknown): string {
   return fileName.toLowerCase().endsWith('.md') ? fileName : `${fileName}.md`;
 }
 
-export function registerTranscriptExportHandler(mainWindow: BrowserWindow): void {
-  ipcMain.handle('transcript:save', async (_event, request: TranscriptSaveRequest) => {
+export function registerTranscriptExportHandler(mainWindow: MainWindowProvider): void {
+  ipcMain.handle('transcript:save', async (event, request: TranscriptSaveRequest) => {
     if (typeof request?.markdown !== 'string') {
       throw new Error('Invalid transcript markdown');
     }
@@ -26,10 +27,15 @@ export function registerTranscriptExportHandler(mainWindow: BrowserWindow): void
 
     let selected: Electron.SaveDialogReturnValue;
     try {
-      selected = await dialog.showSaveDialog(mainWindow, {
+      const owner = (event?.sender && BrowserWindow.fromWebContents(event.sender))
+        || resolveMainWindow(mainWindow);
+      const options: Electron.SaveDialogOptions = {
         defaultPath: safeDefaultPath(request.defaultPath),
         filters: [{ name: 'Markdown', extensions: ['md'] }],
-      });
+      };
+      selected = owner
+        ? await dialog.showSaveDialog(owner, options)
+        : await dialog.showSaveDialog(options);
     } catch {
       throw new Error('Failed to save transcript');
     }