feat(Talk): 系统消息居中展示，订阅 talk:conversation 实时同步

talkSocket 新增 talk:conversation 事件；Talk.vue 收到该事件后：解散或本人被移出则直接移除该会话（在会话中同时清空聊天区并提示），其余变更（改名/公告/角色/移出他人）重新拉取会话列表。

消息区区分 MsgType=3 系统消息，居中灰字展示（不带头像与名字）；api/talk 补齐 MsgType.System。

src/api/talk.ts

@@ -18,8 +18,8 @@ export const ASSET_DOWNLOAD_BASE = 'https://api.gvsds.com/API/Asset/Download'
 /** 会话类型：0=单聊 1=群聊 */
 export const TalkConversationType = { Single: 0, Group: 1 } as const
 
-/** 消息类型：0=文本 1=图片 2=文件（后端契约未显式约定，按此实现，见汇总说明） */
-export const TalkMsgType = { Text: 0, Image: 1, File: 2 } as const
+/** 消息类型：0=文本 1=图片 2=文件 3=系统（后端 MsgType 对齐 manager.py） */
+export const TalkMsgType = { Text: 0, Image: 1, File: 2, System: 3 } as const
 
 /** 群成员角色：0=成员 1=群主 2=管理员（上限由 Entry.GroupAdminLimit 下发） */
 export const TalkMemberRole = { Member: 0, Owner: 1, Admin: 2 } as const
@@ -118,7 +118,7 @@ export interface TalkMessage {
   ConversationUUID: string
   SenderUUID: string
   SenderName: string
-  /** 0=文本 1=图片 2=文件 */
+  /** 0=文本 1=图片 2=文件 3=系统 */
   MsgType: number
   Content: string
   Attachment: TalkAttachment | null

src/utils/talkSocket.ts

@@ -19,6 +19,7 @@ export type TalkServerEvent =
   | 'talk:message'
   | 'talk:read'
   | 'talk:typing'
+  | 'talk:conversation'
   | 'talk:pong'
   | 'talk:error'
 
@@ -31,6 +32,7 @@ const SERVER_EVENTS: TalkServerEvent[] = [
   'talk:message',
   'talk:read',
   'talk:typing',
+  'talk:conversation',
   'talk:pong',
   'talk:error',
 ]

src/views/talk/Talk.vue

@@ -848,6 +848,7 @@ function SetupSocketHandlers(): void {
     subscribeTalkEvent('talk:ready', OnSocketReady),
     subscribeTalkEvent('talk:message', OnSocketMessage),
     subscribeTalkEvent('talk:typing', OnSocketTyping),
+    subscribeTalkEvent('talk:conversation', OnSocketConversation),
     subscribeTalkEvent('talk:error', OnSocketError),
   ]
 }
@@ -870,6 +871,28 @@ function OnSocketMessage(payload: unknown): void {
   PatchConversationOnMessage(message)
 }
 
+/** talk:conversation：群主/管理员操作后的会话级同步（改名 / 公告 / 角色 / 移出 / 转让 / 解散） */
+function OnSocketConversation(payload: unknown): void {
+  const data = payload as
+    | { ConversationUUID?: string; Action?: string; Removed?: string[] }
+    | undefined
+  if (!data?.ConversationUUID) return
+  const conversationUUID = data.ConversationUUID
+  const removedMe = (data.Removed || []).includes(MyUUID.value)
+  // 解散或本人被移出：直接从列表移除（在会话中则同时清空聊天区）
+  if (data.Action === 'dissolved' || removedMe) {
+    if (ActiveUUID.value === conversationUUID) {
+      ActiveUUID.value = ''
+      Messages.value = []
+    }
+    Conversations.value = Conversations.value.filter((c) => c.ConversationUUID !== conversationUUID)
+    ElMessage.warning(removedMe ? '你已被移出该群聊' : '该群聊已解散')
+    return
+  }
+  // 其余变更（改名 / 公告 / 角色 / 追加成员等）：重新拉取会话，保持成员与权限最新
+  void LoadConversations()
+}
+
 /** talk:typing：仅当前会话且非自己时展示 */
 function OnSocketTyping(payload: unknown): void {
   const data = payload as { ConversationUUID?: string; UserUUID?: string } | undefined
@@ -1067,7 +1090,11 @@ onBeforeUnmount(() => {
                   <div v-if="NeedTimeDivider(index)" class="talk-time-divider">
                     {{ FormatMessageTime(message.CreateTime) }}
                   </div>
-                  <div class="talk-msg-row" :class="{ self: IsSelf(message) }">
+                  <!-- 系统消息（群主/管理员操作留痕）：居中灰字，不带头像 -->
+                  <div v-if="message.MsgType === TalkMsgType.System" class="talk-sysmsg">
+                    {{ message.Content }}
+                  </div>
+                  <div v-else class="talk-msg-row" :class="{ self: IsSelf(message) }">
                     <TalkAvatar :user-uuid="message.SenderUUID" :name="message.SenderName" size="small" />
                     <div class="talk-msg-body">
                       <div v-if="IsGroupChat && !IsSelf(message)" class="talk-msg-sender">
@@ -1512,6 +1539,16 @@ onBeforeUnmount(() => {
   margin: 10px 0;
 }
 
+/* ---------- 系统消息（群主/管理员操作留痕） ---------- */
+.talk-sysmsg {
+  margin: 8px 0;
+  text-align: center;
+  font-size: 12px;
+  line-height: 1.6;
+  color: var(--el-text-color-secondary);
+  word-break: break-word;
+}
+
 .talk-msg-row {
   display: flex;
   align-items: flex-start;