feat: add official Codex skill and harden task execution

Install and update artemis-use with task diagnostics and plugin guidance. Preserve cross-device file receipts, review canonical reports, guard stage transitions and reduce small history summaries. Improve exploration lifecycle, request recovery and browser live connections.

apps/showcase_ui/src/app/components/floating-video-player/floating-video-player.component.ts

@@ -70,6 +70,21 @@ export class FloatingVideoPlayerComponent implements OnDestroy {
   public sources = computed(() => this.agentService.recordingSources?.() || []);
   public liveStreamUrl = signal<string>('/api/stream/device-live');
   public liveStreamError = signal<boolean>(false);
+  public pageVisible = signal(!document.hidden);
+
+  @HostListener('document:visibilitychange')
+  @HostListener('window:pageshow')
+  onPageVisibilityChange(): void {
+    this.pageVisible.set(!document.hidden);
+    if (!document.hidden && this.agentService.recordingPlaybackStatus() === 'live') {
+      this.retryLiveStream();
+    }
+  }
+
+  @HostListener('window:pagehide')
+  onPageHide(): void {
+    this.pageVisible.set(false);
+  }
   public activeSegmentIndex = signal<number>(0);
   public currentVideoUrl = computed(() => {
     const segments = this.agentService.activeVideoSegments();