chat search now lists local and server-side hits like the file search, and jumping to old messages pages in history with a progress banner and keeps the hit marked

lib/state/app/modules/chat/bloc/chat_bloc.dart

@@ -180,6 +180,48 @@ class ChatBloc
     }
   }
 
+  /// Pages in older history until [messageId] is held. Returns false when the
+  /// history ends (or a page brings no progress) before reaching it, or when
+  /// [isCancelled] or a chat switch aborts the walk. [onProgress] reports the
+  /// send time of the oldest held message after every page.
+  Future<bool> loadOlderUntil(
+    int messageId, {
+    required bool Function() isCancelled,
+    ValueChanged<DateTime>? onProgress,
+  }) async {
+    final token = innerState?.currentToken ?? '';
+    while (true) {
+      final state = innerState;
+      final response = state?.chatResponse;
+      if (isClosed || isCancelled() || state == null || response == null) {
+        return false;
+      }
+      if (state.currentToken != token) return false;
+      if (response.data.any((m) => m.id == messageId)) return true;
+      final oldestId = _minMessageId(response);
+      if (oldestId > 0 && oldestId < messageId) return false;
+      if (!state.hasMoreOld) return false;
+
+      await loadOlder();
+      // A load started by the scroll listener makes loadOlder() a no-op, and
+      // its result is merged by a queued event — wait until it has landed.
+      if (innerState?.isLoadingOlder ?? false) {
+        try {
+          await stream.firstWhere((s) => !(s.data?.isLoadingOlder ?? false));
+        } on StateError {
+          return false; // bloc closed meanwhile
+        }
+      }
+      final after = innerState?.chatResponse;
+      if (after == null || _minMessageId(after) == oldestId) {
+        if (innerState?.hasMoreOld ?? false) return false;
+      } else {
+        final oldest = after.data.where((m) => m.id == _minMessageId(after));
+        if (oldest.isNotEmpty) onProgress?.call(oldest.first.sentAt);
+      }
+    }
+  }
+
   Future<void> sendServerReadMarker(String token, int messageId) async {
     try {
       await SetReadMarker(