feat(ChatScreen): enhance message input and attachment handling

- Updated ChatInput to manage pending attachments, allowing users to upload multiple images before sending.
- Introduced functionality to remove pending attachments and display their thumbnails in the input area.
- Enhanced ChatScreen to reflect changes in attachment handling, including dynamic messaging during uploads.
- Refactored message segment rendering to support inline text and grouped images, improving visual organization.
- Added constants for maximum pending images to enforce limits on user uploads.

src/screens/message/components/ChatScreen/MessageBubble.tsx

@@ -107,11 +107,14 @@ export const MessageBubble: React.FC<MessageBubbleProps> = ({
   // 检查是否有消息链（必须使用 segments 格式）
   // 安全检查：确保 segments 是数组
   const segments = Array.isArray(message.segments) ? message.segments : [];
-  const hasSegments = segments.length > 0;  
-    // 检查是否是图片消息
+  const hasSegments = segments.length > 0;
+  // 检查是否是图片消息
   const isImage = Array.isArray(segments) && segments.some(s => s.type === 'image');
-  // 检查是否是纯图片消息（只有图片segment，没有文本等其他内容）
-  const isPureImageMessage = isImage && segments.every(s => s.type === 'image' || !s.type);
+  // 纯图片：除 reply 外均为 image（支持多图同条）
+  const segmentsWithoutReply = segments.filter(s => s.type !== 'reply');
+  const isPureImageMessage =
+    segmentsWithoutReply.length > 0 &&
+    segmentsWithoutReply.every(s => s.type === 'image');
   
   // 提取所有图片 segments
   const imageSegments = segments