feat(fe): 宠物照片替代默认头像，身份卡移到首页门面卡

- 首页/我的/切换条：上传过照片就用照片，没有才退回 emoji
- 报告页分享海报：先异步加载头像再开画，画成圆形头像
- 一起生活的天数改成从到家日期算，没填就显示「-」并可点去补
- 身份卡入口从「我的」页移到首页门面卡右上角

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

pets-fe/components/pet-switch/pet-switch.wxml

@@ -2,7 +2,10 @@
   <view wx:for="{{pets}}" wx:key="id"
         class="pet-chip {{item.id === currentId ? 'active' : ''}}"
         data-id="{{item.id}}" bindtap="onPick">
-    <view class="mini-avatar">{{item.emoji}}</view>{{item.name}}
+    <view class="mini-avatar">
+      <image wx:if="{{item.avatar_url}}" class="mini-avatar-img" src="{{item.avatar_url}}" mode="aspectFill"></image>
+      <block wx:else>{{item.emoji}}</block>
+    </view>{{item.name}}
   </view>
   <view wx:if="{{showAdd}}" class="pet-chip" bindtap="onAdd">
     <view class="mini-avatar"><pt-icon name="plus" size="{{30}}"></pt-icon></view>添加

pets-fe/components/pet-switch/pet-switch.wxss

@@ -3,3 +3,5 @@
 }
 .pet-switch .pet-chip{margin-right:20rpx}
 .pet-switch .pet-chip:last-child{margin-right:0}
+.mini-avatar{overflow:hidden}
+.mini-avatar-img{width:100%;height:100%;display:block}