Fix provider selection persistence, queue naming, cancel removal, and update prompts

src/shared/preload-api.ts

@@ -4,6 +4,7 @@ export interface ElectronApi {
   getSnapshot: () => Promise<UiSnapshot>;
   getVersion: () => Promise<string>;
   checkUpdates: () => Promise<UpdateCheckResult>;
+  openExternal: (url: string) => Promise<boolean>;
   updateSettings: (settings: Partial<AppSettings>) => Promise<AppSettings>;
   addLinks: (payload: AddLinksPayload) => Promise<{ addedPackages: number; addedLinks: number; invalidCount: number }>;
   addContainers: (filePaths: string[]) => Promise<{ addedPackages: number; addedLinks: number }>;