UI: Add ChannelTile with logos, search/filter, and design improvements

lib/models/stream_entry.dart

@@ -1,11 +1,18 @@
 class StreamEntry {
   final String title;
   final String url;
+  final String? logo; // optional TVG logo URL
 
-  StreamEntry({required this.title, required this.url});
+  StreamEntry({required this.title, required this.url, this.logo});
+
+  StreamEntry copyWith({String? title, String? url, String? logo}) =>
+      StreamEntry(
+          title: title ?? this.title,
+          url: url ?? this.url,
+          logo: logo ?? this.logo);
 
   @override
-  String toString() => 'StreamEntry(title: $title, url: $url)';
+  String toString() => 'StreamEntry(title: $title, url: $url, logo: $logo)';
 
   @override
   bool operator ==(Object other) =>
@@ -13,8 +20,9 @@ class StreamEntry {
       other is StreamEntry &&
           runtimeType == other.runtimeType &&
           title == other.title &&
-          url == other.url;
+          url == other.url &&
+          logo == other.logo;
 
   @override
-  int get hashCode => title.hashCode ^ url.hashCode;
+  int get hashCode => title.hashCode ^ url.hashCode ^ (logo?.hashCode ?? 0);
 }