fix: Hide long username and instance name in side menu

src/renderer/components/TimelineSpace/SideMenu.vue

@@ -6,7 +6,7 @@
           <div class="avatar" v-if="collapse">
             <img :src="account.avatar" />
           </div>
-          <div v-else>
+          <div class="acct" v-else>
             @{{ account.username }}
             <span class="domain-name">{{ account.domain }}</span>
           </div>
@@ -202,6 +202,12 @@ export default {
       align-items: center;
       justify-content: center;
 
+      .acct {
+        max-width: 117px;
+        overflow: hidden;
+        text-overflow: ellipsis;
+      }
+
       .el-dropdown-link {
         cursor: pointer;
         color: #dcdfe6;