feat(chat): 聊天排版升级微信标准(左右分侧+头像+绿气泡)+is_send数据修复

- is_send 根因:云客消息方向在 mine 字段(isSend 全 null),归一化加 fallback
  +存量回填 60.7 万行(51万收/16万发)——分侧数据首次完整
- MessageBubble:头像(对方=raw headUrl 在左/自己=默认在右)、自己侧隐藏昵称、
  接收白底描边/发送微信绿 #95ec69、气泡列 max-width 78%
- 实测混合对话:13发(绿+头像右)/7收(白+头像左)全部正确

Co-Authored-By: Claude <noreply@anthropic.com>

yunkes/src/components/MessageBubble.vue

@@ -1,6 +1,6 @@
 <script setup lang="ts">
 import { computed } from 'vue'
-import { Microphone, VideoPlay, Document, Picture, Paperclip } from '@element-plus/icons-vue'
+import { Microphone, VideoPlay, Document, Picture, Paperclip, User } from '@element-plus/icons-vue'
 import type { Message } from '@/api/types'
 import { formatDuration, formatTime, wechatTypeLabel } from '@/utils/format'
 
@@ -37,6 +37,13 @@ const emit = defineEmits<{ (e: 'open-detail', message: Message): void }>()
 
 const isSend = computed(() => !!props.message.is_send)
 
+/** 对方头像(raw_json.headUrl);自己侧用默认占位(headUrl 语义不保证是自己)。 */
+const peerAvatarUrl = computed(() => {
+  const rj = props.message.raw_json as Record<string, unknown> | null | undefined
+  const u = rj?.headUrl
+  return typeof u === 'string' && u.startsWith('http') ? u : undefined
+})
+
 // Centered (system/divider) rows ignore direction.
 const isCentered = computed(
   () => props.message.type === 'divider' || props.message.type === 'system',
@@ -187,8 +194,17 @@ const typeTagLabel = computed(() => {
          children (image / video / audio / file link) stop propagation so
          their own clicks don't also open the drawer. -->
     <div v-else class="yk-msg__row yk-msg__row--clickable" @click="emit('open-detail', message)">
+      <!-- 头像:对方=raw headUrl;自己=默认占位(row-reverse 时视觉在右) -->
+      <div class="yk-msg__avatar-wrap">
+        <img v-if="!isSend && peerAvatarUrl" class="yk-msg__avatar" :src="peerAvatarUrl" alt="" />
+        <div v-else class="yk-msg__avatar yk-msg__avatar--ph">
+          <el-icon :size="20"><User /></el-icon>
+        </div>
+      </div>
+
+      <div class="yk-msg__body">
       <div class="yk-msg__meta">
-        <span>{{ senderLabel }}</span>
+        <span v-if="!isSend">{{ senderLabel }}</span>
         <span v-if="timeLabel">{{ timeLabel }}</span>
       </div>
 
@@ -299,6 +315,7 @@ const typeTagLabel = computed(() => {
         <el-icon><Picture /></el-icon>
         [{{ typeTagLabel }}]
       </div>
+      </div>
     </div>
   </div>
 </template>