refactor(unified-collection): drop redundant player toolbar, sharpen header divider

The "channel name + close" bar above the right-pane player was redundant
with the active row in the left list (which already shows the title and
the selection chrome) and was inconsistent with the rest of the app's
live-tv views, which never had it. Closing playback was already
achievable by selecting another channel; the X added cognitive load
without earning its space (ux-similarity-consistency,
ux-cognitive-load-reduce).

Also swap the collection-header border-bottom from
--mat-sys-outline-variant to --app-separator so the divider under
"Favorites" / "Recently viewed" actually carries enough contrast to
read in dark mode (matching the live-epg-panel summary-bar pattern).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Entire-Checkpoint: c2cea9c530e6

libs/portal/shared/ui/src/lib/components/unified-collection/unified-collection-page.component.scss

@@ -28,7 +28,7 @@
     gap: 12px;
     padding: 10px 16px;
     flex-shrink: 0;
-    border-bottom: 1px solid var(--mat-sys-outline-variant);
+    border-bottom: 1px solid var(--app-separator);
 }
 
 .collection-title {

libs/portal/shared/ui/src/lib/components/unified-collection/unified-live-tab.component.html

@@ -51,19 +51,6 @@
                         "
                     />
                 } @else {
-                    <div class="player-toolbar">
-                        <span class="player-title">{{
-                            activeDetail()?.playback?.title
-                        }}</span>
-                        <button
-                            mat-icon-button
-                            (click)="onClose()"
-                            class="close-btn"
-                        >
-                            <mat-icon>close</mat-icon>
-                        </button>
-                    </div>
-
                     @if (player() === 'videojs') {
                         <app-vjs-player
                             [options]="{
@@ -102,20 +89,6 @@
                     shouldUseInlinePlayer() && isLiveEpgPanelCollapsed()
                 "
             >
-                @if (!shouldUseInlinePlayer()) {
-                    <div class="player-toolbar">
-                        <span class="player-title">{{
-                            activeDetail()?.playback?.title
-                        }}</span>
-                        <button
-                            mat-icon-button
-                            (click)="onClose()"
-                            class="close-btn"
-                        >
-                            <mat-icon>close</mat-icon>
-                        </button>
-                    </div>
-                }
                 @if (shouldUseInlinePlayer()) {
                     <app-live-epg-panel
                         [collapsed]="isLiveEpgPanelCollapsed()"

libs/portal/shared/ui/src/lib/components/unified-collection/unified-live-tab.component.scss

@@ -39,32 +39,6 @@
     }
 }
 
-.player-toolbar {
-    display: flex;
-    align-items: center;
-    gap: 8px;
-    padding: 4px 12px 4px 16px;
-    flex-shrink: 0;
-    background: var(--mat-sys-surface-container-low);
-    border-bottom: 1px solid var(--mat-sys-outline-variant);
-    min-height: 40px;
-}
-
-.player-title {
-    flex: 1;
-    min-width: 0;
-    font-size: 13px;
-    font-weight: 500;
-    white-space: nowrap;
-    overflow: hidden;
-    text-overflow: ellipsis;
-    color: var(--mat-sys-on-surface);
-}
-
-.close-btn {
-    flex-shrink: 0;
-}
-
 .radio-close-btn {
     position: absolute;
     top: 16px;