Restore update checks and startup notifications

src/shared/preload-api.ts

@@ -1,8 +1,9 @@
-import type { AddLinksPayload, AppSettings, UiSnapshot } from "./types";
+import type { AddLinksPayload, AppSettings, UiSnapshot, UpdateCheckResult } from "./types";
 
 export interface ElectronApi {
   getSnapshot: () => Promise<UiSnapshot>;
   getVersion: () => Promise<string>;
+  checkUpdates: () => Promise<UpdateCheckResult>;
   updateSettings: (settings: Partial<AppSettings>) => Promise<AppSettings>;
   addLinks: (payload: AddLinksPayload) => Promise<{ addedPackages: number; addedLinks: number; invalidCount: number }>;
   addContainers: (filePaths: string[]) => Promise<{ addedPackages: number; addedLinks: number }>;