feat: 支持聊天多版本答案切换

- 为管理端、公共聊天和用户中心补充回答变体查询与切换能力

- 支持基于指定轮次重新生成并同步前后端多版本状态

- 保留 application.yml 与本地截图文件为未提交状态

easyflow-ui-usercenter/packages/types/src/chat-time.ts

@@ -2,14 +2,31 @@ type ChatTimeTimelineRole = 'assistant' | 'tool' | 'user';
 type ChatTimeToolStatus = 'TOOL_CALL' | 'TOOL_RESULT';
 type ChatTimeThinkingStatus = 'end' | 'thinking';
 
+interface ChatTimeRoundMeta {
+  messageKind?: string;
+  roundId?: number | string;
+  roundNo?: number;
+  selectedVariantIndex?: number;
+  switchable?: boolean;
+  variantCount?: number;
+  variantIndex?: number;
+}
+
 interface ChatTimeTimelineItemBase {
   created: number | string;
   id: string;
   loading?: boolean;
+  messageKind?: string;
   placement: 'end' | 'start';
+  roundId?: string;
+  roundNo?: number;
   role: ChatTimeTimelineRole;
+  selectedVariantIndex?: number;
   senderName?: string;
+  switchable?: boolean;
   typing?: boolean;
+  variantCount?: number;
+  variantIndex?: number;
 }
 
 interface ChatTimeAssistantThinkingSegment {
@@ -66,14 +83,22 @@ interface ChatTimeHistoryRecord {
   loading?: boolean;
   placement?: 'end' | 'start';
   role?: string;
+  roundId?: number | string;
+  roundNo?: number;
+  selectedVariantIndex?: number;
   senderName?: string;
   senderRole?: string;
+  switchable?: boolean;
   typing?: boolean;
+  variantCount?: number;
+  variantIndex?: number;
+  messageKind?: string;
 }
 
-interface ChatTimeToolMutationPayload {
+interface ChatTimeToolMutationPayload extends ChatTimeRoundMeta {
   created?: number | string;
   name?: string;
+  regenerate?: boolean;
   result?: any;
   toolCallId?: string;
   value?: any;
@@ -85,6 +110,7 @@ export type {
   ChatTimeAssistantTextSegment,
   ChatTimeAssistantThinkingSegment,
   ChatTimeHistoryRecord,
+  ChatTimeRoundMeta,
   ChatTimeThinkingStatus,
   ChatTimeTimelineItem,
   ChatTimeTimelineItemBase,