perf: 懒加载TemplateGallery组件，扩展动画类型选项

- 将Animation/Exercise/CoursewareDetail中的TemplateGallery改为异步组件加载
  减少页面初始加载体积，仅在用户打开模板库时才加载294KB的游戏模板代码
- 为教学动画添加更多学科类型：语文、英语、历史，同时更新typeLabel映射

frontend/src/views/Animation.vue

@@ -208,7 +208,7 @@ import { exportHtml } from '@/api/ai'
 import { publishResource } from '@/api/resource'
 import HtmlPreview from '@/components/common/HtmlPreview.vue'
 import MaterialPicker from '@/components/common/MaterialPicker.vue'
-import TemplateGallery from '@/components/common/TemplateGallery.vue'
+const TemplateGallery = defineAsyncComponent(() => import('@/components/common/TemplateGallery.vue'))
 import { useUserStore } from '@/stores/user'
 import { downloadBlob } from '@/utils/download'
 import { buildMaterialPromptBlock, type MaterialContextItem } from '@/utils/materialContext'
@@ -544,6 +544,9 @@ function typeLabel(type: string) {
     chemistry: '化学',
     biology: '生物',
     geography: '地理',
+    chinese: '语文',
+    english: '英语',
+    history: '历史',
     general: '通用',
   }
   return map[type] || '通用'

frontend/src/views/CoursewareDetail.vue

@@ -169,7 +169,7 @@ import { exportHtml } from '@/api/ai'
 import { createCoursewareShare, exportCoursewareDocx, getCourseware, updateCourseware } from '@/api/courseware'
 import { publishResource } from '@/api/resource'
 import HtmlPreview from '@/components/common/HtmlPreview.vue'
-import TemplateGallery from '@/components/common/TemplateGallery.vue'
+const TemplateGallery = defineAsyncComponent(() => import('@/components/common/TemplateGallery.vue'))
 import { downloadBlob } from '@/utils/download'
 import { coursewareThemes, applyThemeToPage, detectPageTheme, getTheme } from '@/utils/coursewareThemes'
 

frontend/src/views/Exercise.vue

@@ -289,7 +289,7 @@ import { aiGenerateExercise, createExercise, deleteExercise, exportExerciseDocx,
 import { publishResource } from '@/api/resource'
 import MarkdownContent from '@/components/common/MarkdownContent.vue'
 import HtmlPreview from '@/components/common/HtmlPreview.vue'
-import TemplateGallery from '@/components/common/TemplateGallery.vue'
+const TemplateGallery = defineAsyncComponent(() => import('@/components/common/TemplateGallery.vue'))
 import MaterialPicker from '@/components/common/MaterialPicker.vue'
 import { useUserStore } from '@/stores/user'
 import { downloadBlob } from '@/utils/download'