chore(sfc-playground): highlight the active version in dropdown (#9045)

packages/sfc-playground/src/Header.vue

@@ -24,7 +24,7 @@ const vueVersion = ref(`@${currentCommit}`)
 async function setVueVersion(v: string) {
   vueVersion.value = `loading...`
   await store.setVueVersion(v)
-  vueVersion.value = `v${v}`
+  vueVersion.value = v
 }
 
 function resetVueVersion() {

packages/sfc-playground/src/VersionSelect.vue

@@ -74,8 +74,8 @@ onMounted(() => {
 
     <ul class="versions" :class="{ expanded }">
       <li v-if="!versions"><a>loading versions...</a></li>
-      <li v-for="version of versions">
-        <a @click="setVersion(version)">v{{ version }}</a>
+      <li v-for="ver of versions" :class="{ active: ver === version }">
+        <a @click="setVersion(ver)">v{{ ver }}</a>
       </li>
       <div @click="expanded = false">
         <slot />
@@ -111,4 +111,8 @@ onMounted(() => {
   border-top: 6px solid #aaa;
   margin-left: 8px;
 }
+
+.versions .active a {
+  color: var(--green);
+}
 </style>