Introduce GptMarkdownBuilder and wire into message widgets

packages/flutter_chat_core/lib/src/utils/typedefs.dart

@@ -36,3 +36,13 @@ typedef ChatItem =
       int? messageGroupingTimeoutInSeconds,
       bool? isRemoved,
     });
+
+/// Builder signature for rendering streamed Markdown content.
+/// Used by widgets like `FlyerChatTextStreamMessage` to customize Markdown rendering.
+typedef GptMarkdownBuilder =
+    Widget Function(
+      BuildContext context,
+      String text,
+      TextStyle? paragraphStyle,
+      void Function(String url, String title)? onLinkTap,
+    );

packages/flyer_chat_text_message/lib/src/flyer_chat_text_message.dart

@@ -73,6 +73,10 @@ class FlyerChatTextMessage extends StatelessWidget {
   /// The callback function to handle link clicks.
   final void Function(String url, String title)? onLinkTap;
 
+  /// Optional builder to customize how Markdown is rendered.
+  /// If provided, it will be used instead of the default [GptMarkdown] widget.
+  final GptMarkdownBuilder? gptMarkdownBuilder;
+
   /// The position of the link preview widget relative to the text.
   /// If set to [LinkPreviewPosition.none], the link preview widget will not be displayed.
   /// A [LinkPreviewBuilder] must be provided for the preview to be displayed.
@@ -102,6 +106,7 @@ class FlyerChatTextMessage extends StatelessWidget {
     this.timeAndStatusPosition = TimeAndStatusPosition.end,
     this.timeAndStatusPositionInlineInsets = const EdgeInsets.only(bottom: 2),
     this.onLinkTap,
+    this.gptMarkdownBuilder,
     this.linkPreviewPosition = LinkPreviewPosition.bottom,
     this.topWidget,
   });
@@ -137,20 +142,31 @@ class FlyerChatTextMessage extends StatelessWidget {
             )
             : null;
 
-    final textContent = GptMarkdownTheme(
-      gptThemeData: GptMarkdownTheme.of(context).copyWith(
-        linkColor: isSentByMe ? sentLinksColor : receivedLinksColor,
-        linkHoverColor: isSentByMe ? sentLinksColor : receivedLinksColor,
-      ),
-      child: GptMarkdown(
-        message.text,
-        style:
-            _isOnlyEmoji
-                ? paragraphStyle?.copyWith(fontSize: onlyEmojiFontSize)
-                : paragraphStyle,
-        onLinkTap: onLinkTap,
-      ),
-    );
+    final effectiveParagraphStyle =
+        _isOnlyEmoji
+            ? paragraphStyle?.copyWith(fontSize: onlyEmojiFontSize)
+            : paragraphStyle;
+
+    final textContent =
+        gptMarkdownBuilder != null
+            ? gptMarkdownBuilder!(
+              context,
+              message.text,
+              effectiveParagraphStyle,
+              onLinkTap,
+            )
+            : GptMarkdownTheme(
+              gptThemeData: GptMarkdownTheme.of(context).copyWith(
+                linkColor: isSentByMe ? sentLinksColor : receivedLinksColor,
+                linkHoverColor:
+                    isSentByMe ? sentLinksColor : receivedLinksColor,
+              ),
+              child: GptMarkdown(
+                message.text,
+                style: effectiveParagraphStyle,
+                onLinkTap: onLinkTap,
+              ),
+            );
 
     final linkPreviewWidget =
         linkPreviewPosition != LinkPreviewPosition.none

packages/flyer_chat_text_stream_message/lib/src/flyer_chat_text_stream_message.dart

@@ -92,6 +92,10 @@ class FlyerChatTextStreamMessage extends StatefulWidget {
   /// The callback function to handle link clicks.
   final void Function(String url, String title)? onLinkTap;
 
+  /// Optional builder to customize how Markdown is rendered.
+  /// If provided, it will be used instead of the default [GptMarkdown] widget.
+  final GptMarkdownBuilder? gptMarkdownBuilder;
+
   /// The text to display while in the loading state. Defaults to "Thinking".
   final String loadingText;
 
@@ -128,6 +132,7 @@ class FlyerChatTextStreamMessage extends StatefulWidget {
     this.chunkAnimationDuration = const Duration(milliseconds: 350),
     this.mode = TextStreamMessageMode.animatedOpacity,
     this.onLinkTap,
+    this.gptMarkdownBuilder,
     this.loadingText = 'Thinking',
     this.shimmerBaseColor,
     this.shimmerHighlightColor,
@@ -371,6 +376,15 @@ class _FlyerChatTextStreamMessageState extends State<FlyerChatTextStreamMessage>
 
     if (widget.streamState is StreamStateCompleted) {
       final state = widget.streamState as StreamStateCompleted;
+      final builder = widget.gptMarkdownBuilder;
+      if (builder != null) {
+        return builder(
+          context,
+          state.finalText,
+          paragraphStyle,
+          widget.onLinkTap,
+        );
+      }
       return GptMarkdown(
         state.finalText,
         style: paragraphStyle,
@@ -392,6 +406,15 @@ class _FlyerChatTextStreamMessageState extends State<FlyerChatTextStreamMessage>
 
       if (widget.mode == TextStreamMessageMode.instantMarkdown) {
         final combinedText = _segments.map((s) => s.text).join('');
+        final builder = widget.gptMarkdownBuilder;
+        if (builder != null) {
+          return builder(
+            context,
+            combinedText,
+            paragraphStyle,
+            widget.onLinkTap,
+          );
+        }
         return GptMarkdown(combinedText, style: paragraphStyle);
       } else {
         return RichText(