feat: add snjs package

packages/snjs/lib/ApplicationGroup/ApplicationGroupEvent.ts

@@ -0,0 +1,21 @@
+import { ApplicationInterface, DeinitMode, DeinitSource } from '@standardnotes/services'
+import { DescriptorRecord } from './DescriptorRecord'
+
+export enum ApplicationGroupEvent {
+  PrimaryApplicationSet = 'PrimaryApplicationSet',
+  DescriptorsDataChanged = 'DescriptorsDataChanged',
+  DeviceWillRestart = 'DeviceWillRestart',
+}
+
+export interface ApplicationGroupEventData {
+  [ApplicationGroupEvent.PrimaryApplicationSet]: {
+    application: ApplicationInterface
+  }
+  [ApplicationGroupEvent.DeviceWillRestart]: {
+    source: DeinitSource
+    mode: DeinitMode
+  }
+  [ApplicationGroupEvent.DescriptorsDataChanged]: {
+    descriptors: DescriptorRecord
+  }
+}