위젯 추가 팝업 수정

desktop/src/widgetPickerEvents.ts

@@ -0,0 +1,8 @@
+/** Tauri 위젯 ↔ 위젯 선택 창 이벤트 */
+export const WIDGET_PICKER_SELECT_EVENT = 'gc-widget-picker-select';
+
+export interface WidgetPickerSelectPayload {
+  instanceId: string;
+  slotId: string;
+  widgetType: string;
+}