perf(ui): lazy-load content-card images + OnPush on sources filters panel

Two small focused changes from an Angular perf audit.

content-card lazy loading
ContentCard is the building block for catalog grids and rails — Xtream
recently-added (3 rails × 20 = 60 cards on first paint), Xtream/Stalker
search results, unified favorites/recent grids. The poster <img> had
no loading attribute, so every off-screen card eagerly fetched its
poster from the Xtream/Stalker server on initial render. Same fix
already in place on the dashboard rail's separate <img>; mirror it on
the shared ContentCard so every consumer benefits.

Add loading="lazy" decoding="async" to both <img> tags (real poster
and the default-poster fallback). Browser defers off-screen requests;
no JS changes.

OnPush on workspace-sources-filters-panel
The sources filters panel renders one row per filter option and
displays {{ getTypeCount(option.id) }} per row — that method is a
plain Map lookup but fires every CD cycle under default change
detection. The component is signal-only (computed + selectSignal, no
subscribes) so the OnPush conversion is purely additive.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Entire-Checkpoint: f957cd9849e0

libs/portal/shared/ui/src/lib/components/content-card/content-card.component.html

@@ -17,6 +17,8 @@
                 [alt]="title()"
                 (error)="onImageError($event)"
                 class="poster"
+                loading="lazy"
+                decoding="async"
             />
         } @else if (showPlaceholder()) {
             <div class="poster-placeholder">
@@ -27,6 +29,8 @@
                 src="./assets/images/default-poster.png"
                 [alt]="title()"
                 class="poster"
+                loading="lazy"
+                decoding="async"
             />
         }
 

libs/workspace/shell/feature/src/lib/workspace-sources-filters-panel/workspace-sources-filters-panel.component.ts

@@ -1,4 +1,9 @@
-import { computed, Component, inject } from '@angular/core';
+import {
+    ChangeDetectionStrategy,
+    Component,
+    computed,
+    inject,
+} from '@angular/core';
 import { MatIcon } from '@angular/material/icon';
 import { MatListModule } from '@angular/material/list';
 import { Store } from '@ngrx/store';
@@ -25,6 +30,7 @@ const ALL_FILTERS = ['m3u', 'xtream', 'stalker'];
     imports: [MatIcon, MatListModule, TranslatePipe],
     templateUrl: './workspace-sources-filters-panel.component.html',
     styleUrl: './workspace-sources-filters-panel.component.scss',
+    changeDetection: ChangeDetectionStrategy.OnPush,
 })
 export class WorkspaceSourcesFiltersPanelComponent {
     private readonly store = inject(Store);