chore(speaking): rename default AI from Tom to Amy

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/views/Editor/EnglishSpeaking/preview/DialogueChatView.vue

@@ -564,7 +564,7 @@ interface Props {
 const props = withDefaults(defineProps<Props>(), {
   topic: '',
   keywords: () => ['animal', 'zoo', 'cute', 'favorite'],
-  aiName: 'Tom',
+  aiName: 'Amy',
   aiAvatar: '😊',
   totalRounds: 3,
   showEnglishText: true,

src/views/Editor/EnglishSpeaking/preview/TopicDiscussionPreview.vue

@@ -130,7 +130,7 @@ const runtimeUserId = computed(() => runtimeParams.value.userId || '')
 
 const mockRole: PreviewAIRole = {
   id: 'tom',
-  name: 'Tom',
+  name: 'Amy',
   avatar: '😊',
   identity: 'Friendly Teacher',
   personality: 'Patient and encouraging',