remove import teaching design feature

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

src/components/WorkspaceToolbar.vue

@@ -8,7 +8,6 @@ const props = defineProps<{
 }>()
 
 defineEmits<{
-  upload: []
   print: []
   export: []
   clear: []
@@ -29,7 +28,6 @@ const saveStatusLabel: Record<SaveStatus, string> = {
 <template>
   <header class="workspace-toolbar">
     <button type="button" data-testid="back" @click="$emit('back')">返回列表</button>
-    <button type="button" data-testid="upload" @click="$emit('upload')">导入教案</button>
     <button type="button" data-testid="generate" @click="$emit('generate')">生成一篇</button>
     <button type="button" data-testid="batch-generate" @click="$emit('batchGenerate')">批量生成</button>
     <button type="button" data-testid="print" :disabled="lessonCount === 0" @click="$emit('print')">打印整册</button>