feat: merge generate buttons into a single dropdown in WorkspaceToolbar

- Wire GenerateMenuButton component into WorkspaceToolbar.vue
- Update WorkspaceToolbar.test.ts to open dropdown before clicking menu items
- Update WorkspaceView.test.ts to open dropdown before clicking generate buttons

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

src/components/WorkspaceToolbar.test.ts

@@ -14,21 +14,31 @@ describe('WorkspaceToolbar', () => {
     expect(wrapper.text()).toContain('共 3 课')
   })
 
-  it('emits generate when the generate button is clicked', async () => {
+  it('emits generate when the generate menu item is clicked', async () => {
     const wrapper = mountToolbar(3)
+    await wrapper.get('button[data-testid="generate-menu-toggle"]').trigger('click')
     await wrapper.get('button[data-testid="generate"]').trigger('click')
     expect(wrapper.emitted('generate')).toHaveLength(1)
   })
 
+  it('emits batchGenerate when the batch-generate menu item is clicked', async () => {
+    const wrapper = mountToolbar(3)
+    await wrapper.get('button[data-testid="generate-menu-toggle"]').trigger('click')
+    await wrapper.get('button[data-testid="batch-generate"]').trigger('click')
+    expect(wrapper.emitted('batchGenerate')).toHaveLength(1)
+  })
+
   it('emits back when the back button is clicked', async () => {
     const wrapper = mountToolbar(0)
     await wrapper.get('button[data-testid="back"]').trigger('click')
     expect(wrapper.emitted('back')).toHaveLength(1)
   })
 
-  it('keeps generate and back enabled even with no lessons', () => {
+  it('keeps the generate menu toggle and back button enabled even with no lessons', () => {
     const wrapper = mountToolbar(0)
-    expect(wrapper.get('button[data-testid="generate"]').attributes('disabled')).toBeUndefined()
+    expect(
+      wrapper.get('button[data-testid="generate-menu-toggle"]').attributes('disabled'),
+    ).toBeUndefined()
     expect(wrapper.get('button[data-testid="back"]').attributes('disabled')).toBeUndefined()
   })
 

src/components/WorkspaceToolbar.vue

@@ -1,5 +1,6 @@
 <script setup lang="ts">
 import type { SaveStatus } from '../composables/useTeachingBook'
+import GenerateMenuButton from './GenerateMenuButton.vue'
 
 const props = defineProps<{
   lessonCount: number
@@ -28,8 +29,7 @@ const saveStatusLabel: Record<SaveStatus, string> = {
 <template>
   <header class="workspace-toolbar">
     <button type="button" data-testid="back" @click="$emit('back')">返回列表</button>
-    <button type="button" data-testid="batch-generate" @click="$emit('batchGenerate')">批量生成</button>
-    <button type="button" data-testid="generate" @click="$emit('generate')">生成一篇</button>
+    <GenerateMenuButton @generate="$emit('generate')" @batch-generate="$emit('batchGenerate')" />
     <button type="button" data-testid="print" :disabled="lessonCount === 0" @click="$emit('print')">打印整册</button>
     <button type="button" data-testid="export" :disabled="lessonCount === 0" @click="$emit('export')">导出 MD</button>
     <button type="button" data-testid="clear" :disabled="lessonCount === 0" @click="$emit('clear')">清空</button>

src/components/WorkspaceView.test.ts

@@ -92,6 +92,7 @@ describe('WorkspaceView', () => {
     const wrapper = mount(WorkspaceView, { props: { bookId: 'b1' } })
     await flushPromises()
 
+    await wrapper.get('[data-testid="generate-menu-toggle"]').trigger('click')
     await wrapper.get('[data-testid="generate"]').trigger('click')
     const dialog = wrapper.getComponent(GenerateLessonDialog)
 
@@ -128,6 +129,7 @@ describe('WorkspaceView', () => {
     const wrapper = mount(WorkspaceView, { props: { bookId: 'b1' } })
     await flushPromises()
 
+    await wrapper.get('[data-testid="generate-menu-toggle"]').trigger('click')
     await wrapper.get('[data-testid="batch-generate"]').trigger('click')
     wrapper.getComponent(BatchGenerateDialog).vm.$emit('start', [
       '第一课',