perf(services): keep only the shared startup inventory read (J1)

Drop the startup deferral gate, its kill switch and the deferred loads:
they lowered renderer.ipcCallsToFirstCard but moved neither
spawnToFirstCardMs nor load->card beyond drift, and they grew
renderer.initialBytes. Keep the shared in-flight inventory read, inline
it in PlaylistsService with short property names, and copy the joiner's
result with structuredClone (the Electron renderer has it; the services
test setup polyfills it for jsdom).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

libs/workspace/dashboard/data-access/src/lib/dashboard-data.service.spec.ts

@@ -7,11 +7,7 @@ import {
     selectPlaylistsLoadingFlag,
 } from '@iptvnator/m3u-state';
 import { of, Subject } from 'rxjs';
-import {
-    DatabaseService,
-    PlaylistsService,
-    StartupDeferralService,
-} from '@iptvnator/services';
+import { DatabaseService, PlaylistsService } from '@iptvnator/services';
 import {
     PlaybackPositionData,
     Playlist,
@@ -274,30 +270,6 @@ describe('DashboardDataService', () => {
         expect(service.dashboardReady()).toBe(false);
     });
 
-    it('holds the page-entry reload until the first screen rendered', async () => {
-        let openGate!: () => void;
-        jest.spyOn(
-            TestBed.inject(StartupDeferralService),
-            'whenFirstContentRendered'
-        ).mockReturnValue(new Promise<void>((resolve) => (openGate = resolve)));
-        const recent = jest
-            .spyOn(service, 'reloadGlobalRecentItems')
-            .mockResolvedValue(undefined);
-        const favorites = jest
-            .spyOn(service, 'reloadGlobalFavorites')
-            .mockResolvedValue(undefined);
-
-        const reload = service.reloadForPageEntry();
-        await Promise.resolve();
-        expect(recent).not.toHaveBeenCalled();
-        expect(favorites).not.toHaveBeenCalled();
-
-        openGate();
-        await reload;
-        expect(recent).toHaveBeenCalledTimes(1);
-        expect(favorites).toHaveBeenCalledTimes(1);
-    });
-
     it('keeps dashboardReady false until xtream recently added finishes its first load', async () => {
         expect(service.dashboardReady()).toBe(false);
 

libs/workspace/dashboard/data-access/src/lib/dashboard-data.service.ts

@@ -20,7 +20,6 @@ import {
     GlobalRecentlyAddedKind,
     PlaylistsService,
     RuntimeCapabilitiesService,
-    StartupDeferralService,
 } from '@iptvnator/services';
 import {
     XTREAM_DATA_SOURCE,
@@ -117,7 +116,6 @@ export class DashboardDataService {
     private readonly xtreamDataSource = inject(XTREAM_DATA_SOURCE);
     private readonly playlistsService = inject(PlaylistsService);
     private readonly runtime = inject(RuntimeCapabilitiesService);
-    private readonly startupDeferral = inject(StartupDeferralService);
     private readonly ngZone = inject(NgZone);
     private readonly translate = inject(TranslateService);
     private readonly playbackPositions = inject(PORTAL_PLAYBACK_POSITIONS);
@@ -501,19 +499,6 @@ export class DashboardDataService {
 
     readonly quickRecent = computed(() => this.recentPlaylists().slice(0, 4));
 
-    /**
-     * Page-entry reload of recent items and favorites. On launch it waits for
-     * the first rendered screen (journey J1) and the rails keep their
-     * skeletons meanwhile; later entries find the gate already open.
-     */
-    async reloadForPageEntry(): Promise<void> {
-        await this.startupDeferral.whenFirstContentRendered();
-        await Promise.all([
-            this.reloadGlobalRecentItems(),
-            this.reloadGlobalFavorites(),
-        ]);
-    }
-
     async reloadGlobalRecentItems(): Promise<void> {
         if (!this.globalRecentLoaded()) {
             this.globalRecentLoadingState.set(true);