Light theme default + yt-dlp search fallback

lib/models/channel_rank_item.dart

@@ -0,0 +1,25 @@
+import 'subscription_channel.dart';
+
+class ChannelRankItem {
+  const ChannelRankItem({
+    required this.channel,
+    required this.personalViewCount,
+    required this.distinctVideoCount,
+    required this.topVideoPersonalViews,
+    this.topVideoTitle,
+  });
+
+  final SubscriptionChannel channel;
+
+  /// Number of times the user actually opened videos from this channel in
+  /// YouTube Personal. This is the primary ranking metric.
+  final int personalViewCount;
+
+  /// Distinct history videos currently known for this channel.
+  final int distinctVideoCount;
+
+  /// Personal repeat count for the user's most watched known video.
+  final int topVideoPersonalViews;
+
+  final String? topVideoTitle;
+}