fix(sdk): 修复历史会话不显示图片附件

- MessageConverter 落库时持久化多模态 Media 到 metadata._media
- ConversationService 历史消息接口提取 _media 为顶层 images 字段
- SDK 前端历史映射补齐 images，复用 renderUserBubble 附件渲染

client/src/api.ts

@@ -649,7 +649,7 @@ export async function fetchConversationList(
  * 使用 /ai/sdk/conversation/{id}/messages，含账户归属校验
  */
 export async function fetchConversationMessages(conversationId: string): Promise<{
-  messages: Array<{ messageType: string; content: string; createTime: string }>;
+  messages: Array<{ messageType: string; content: string; createTime: string; images?: ImageAttachment[] }>;
   total: number;
 }> {
   const params = new URLSearchParams();

client/src/chat.ts

@@ -181,6 +181,12 @@ async function loadHistoryFromBackend(): Promise<void> {
         id: uuid(),
         role: msg.messageType === 'USER' ? 'user' : 'ai' as const,
         content: msg.content,
+        images: (msg.images || []).map((i) => ({
+          name: i.name || '',
+          url: i.url,
+          mimeType: i.mimeType,
+          size: i.size,
+        })),
         timestamp: new Date(msg.createTime).getTime(),
       }));
 
@@ -1019,6 +1025,12 @@ async function switchToConversation(conversationId: string): Promise<void> {
         id: uuid(),
         role: msg.messageType === 'USER' ? 'user' : 'ai' as const,
         content: msg.content,
+        images: (msg.images || []).map((i) => ({
+          name: i.name || '',
+          url: i.url,
+          mimeType: i.mimeType,
+          size: i.size,
+        })),
         timestamp: new Date(msg.createTime).getTime(),
       }));
 

src/main/java/com/wok/supportbot/converter/MessageConverter.java

@@ -2,6 +2,9 @@ package com.wok.supportbot.converter;
 
 import com.wok.supportbot.entity.ChatMessage;
 import org.springframework.ai.chat.messages.*;
+import org.springframework.ai.content.Media;
+import org.springframework.util.MimeType;
+import org.springframework.util.MimeTypeUtils;
 
 import java.util.*;
 
@@ -16,6 +19,8 @@ public class MessageConverter {
     private static final String META_KEY_TOOL_CALLS = "_toolCalls";
     /** metadata 中存储 toolResponses 的内部键名 */
     private static final String META_KEY_TOOL_RESPONSES = "_toolResponses";
+    /** metadata 中存储多模态图片 Media 的内部键名 */
+    private static final String META_KEY_MEDIA = "_media";
 
     /**
      * 将 Spring AI Message 转换为数据库实体 ChatMessage
@@ -54,6 +59,26 @@ public class MessageConverter {
             metadata.put(META_KEY_TOOL_RESPONSES, responsesJson);
         }
 
+        // 处理多模态图片 Media（仅用户消息携带），序列化到 metadata 供历史会话还原图片附件
+        if (message instanceof UserMessage userMessage) {
+            List<Media> mediaList = userMessage.getMedia();
+            if (mediaList != null && !mediaList.isEmpty()) {
+                List<Map<String, String>> mediaJson = new ArrayList<>();
+                for (Media media : mediaList) {
+                    Map<String, String> m = new LinkedHashMap<>();
+                    Object data = media.getData();
+                    if (data != null) {
+                        m.put("url", String.valueOf(data));
+                    }
+                    if (media.getMimeType() != null) {
+                        m.put("mimeType", media.getMimeType().toString());
+                    }
+                    mediaJson.add(m);
+                }
+                metadata.put(META_KEY_MEDIA, mediaJson);
+            }
+        }
+
         return ChatMessage.builder()
                 .conversationId(conversationId)
                 .messageType(message.getMessageType())
@@ -78,7 +103,11 @@ public class MessageConverter {
                 : new HashMap<>();
 
         return switch (messageType) {
-            case USER -> new UserMessage(text);
+            case USER -> {
+                List<Media> media = extractMedia(cleanMetadata);
+                yield media.isEmpty() ? new UserMessage(text)
+                        : UserMessage.builder().text(text).media(media).build();
+            }
             case ASSISTANT -> {
                 List<AssistantMessage.ToolCall> toolCalls = extractToolCalls(cleanMetadata);
                 yield new AssistantMessage(text, cleanMetadata, toolCalls);
@@ -135,4 +164,43 @@ public class MessageConverter {
         }
         return result;
     }
+
+    /**
+     * 从 metadata 中提取并移除 _media 键，反序列化为 Media 列表。
+     * 无媒体时返回空列表，保证多轮记忆不丢图片。
+     */
+    @SuppressWarnings("unchecked")
+    private static List<Media> extractMedia(Map<String, Object> metadata) {
+        Object raw = metadata.remove(META_KEY_MEDIA);
+        if (!(raw instanceof List<?> list) || list.isEmpty()) {
+            return List.of();
+        }
+        List<Media> result = new ArrayList<>();
+        for (Object item : list) {
+            if (item instanceof Map) {
+                Map<?, ?> map = (Map<?, ?>) item;
+                Object url = map.get("url");
+                if (url == null) {
+                    continue;
+                }
+                result.add(Media.builder()
+                        .data(url.toString())
+                        .mimeType(parseMimeTypeSafely(map.get("mimeType")))
+                        .build());
+            }
+        }
+        return result;
+    }
+
+    /** 安全解析 MIME 类型，缺失或非法时兜底为 image/png（与图片扩展名推断逻辑一致） */
+    private static MimeType parseMimeTypeSafely(Object mimeType) {
+        if (mimeType == null) {
+            return MimeTypeUtils.IMAGE_PNG;
+        }
+        try {
+            return MimeTypeUtils.parseMimeType(mimeType.toString());
+        } catch (Exception e) {
+            return MimeTypeUtils.IMAGE_PNG;
+        }
+    }
 }

src/main/java/com/wok/supportbot/service/ConversationService.java

@@ -283,7 +283,14 @@ public class ConversationService {
             item.put("conversationId", msg.getConversationId());
             item.put("messageType", msg.getMessageType());
             item.put("content", msg.getContent());
-            item.put("metadata", msg.getMetadata());
+            // 复制 metadata，提取内部键 _media 为顶层 images 字段（供历史会话还原图片附件），避免内部键泄漏
+            Map<String, Object> metadata = msg.getMetadata() != null
+                    ? new LinkedHashMap<>(msg.getMetadata()) : new LinkedHashMap<>();
+            Object media = metadata.remove("_media");
+            item.put("metadata", metadata);
+            if (media instanceof List<?> mediaList && !mediaList.isEmpty()) {
+                item.put("images", mediaList);
+            }
             item.put("createTime", msg.getCreateTime());
             result.add(item);
         }