[미리보기] 버튼 상태 저장, 앱 실행시 직전 상태 적용

src/main/ipc/folder.js

@@ -57,6 +57,17 @@ function register(mainWindow) {
   });
 
   ipcMain.handle('reveal-folder', (_e, folderPath) => shell.openPath(folderPath));
+
+  ipcMain.handle('get-preview-on', () => {
+    const cfg = readConfig();
+    return cfg.previewOn !== false; // 기본값 true
+  });
+
+  ipcMain.handle('set-preview-on', (_e, on) => {
+    const cfg = readConfig();
+    cfg.previewOn = on;
+    writeConfig(cfg);
+  });
 }
 
 module.exports = { register };