add ticker page bloc and avatar disk cache

lib/api/marianumconnect/queries/get_ticker_page/get_ticker_page_response.dart

@@ -39,6 +39,11 @@ class TickerPageResponse {
   final String? hash;
   final String? webUrl;
 
+  /// ISO timestamp the page was last published/updated (`ticker_pages.published_at`),
+  /// shown as "Aktualisiert am …" — the same date the web view displays. Null
+  /// when the page has never been published.
+  final String? publishedAt;
+
   TickerPageResponse({
     required this.schemaVersion,
     this.slug,
@@ -52,6 +57,7 @@ class TickerPageResponse {
     this.filename,
     this.hash,
     this.webUrl,
+    this.publishedAt,
   });
 
   factory TickerPageResponse.fromJson(Map<String, dynamic> json) =>

lib/api/marianumconnect/queries/get_ticker_page/get_ticker_page_response.g.dart

@@ -20,6 +20,7 @@ TickerPageResponse _$TickerPageResponseFromJson(Map<String, dynamic> json) =>
       filename: json['filename'] as String?,
       hash: json['hash'] as String?,
       webUrl: json['webUrl'] as String?,
+      publishedAt: json['publishedAt'] as String?,
     );
 
 Map<String, dynamic> _$TickerPageResponseToJson(TickerPageResponse instance) =>
@@ -36,4 +37,5 @@ Map<String, dynamic> _$TickerPageResponseToJson(TickerPageResponse instance) =>
       'filename': instance.filename,
       'hash': instance.hash,
       'webUrl': instance.webUrl,
+      'publishedAt': instance.publishedAt,
     };