feat: add GenerateMenuButton dropdown component

Implements a dropdown menu button component with generate and batch generate options. Includes click-outside and Escape-key menu closing behavior.

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

src/components/GenerateMenuButton.test.ts

@@ -0,0 +1,62 @@
+import { mount } from '@vue/test-utils'
+import { describe, expect, it } from 'vitest'
+import GenerateMenuButton from './GenerateMenuButton.vue'
+
+describe('GenerateMenuButton', () => {
+  it('renders the toggle button with the menu closed by default', () => {
+    const wrapper = mount(GenerateMenuButton, { attachTo: document.body })
+    expect(wrapper.get('button[data-testid="generate-menu-toggle"]').text()).toContain('生成教案')
+    expect(wrapper.find('[data-testid="generate"]').exists()).toBe(false)
+    expect(wrapper.find('[data-testid="batch-generate"]').exists()).toBe(false)
+    wrapper.unmount()
+  })
+
+  it('opens the menu when the toggle button is clicked', async () => {
+    const wrapper = mount(GenerateMenuButton, { attachTo: document.body })
+    await wrapper.get('button[data-testid="generate-menu-toggle"]').trigger('click')
+    expect(wrapper.get('[data-testid="generate"]').isVisible()).toBe(true)
+    expect(wrapper.get('[data-testid="batch-generate"]').isVisible()).toBe(true)
+    wrapper.unmount()
+  })
+
+  it('emits generate and closes the menu when "生成一篇" is clicked', async () => {
+    const wrapper = mount(GenerateMenuButton, { attachTo: document.body })
+    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)
+    expect(wrapper.find('[data-testid="generate"]').exists()).toBe(false)
+    wrapper.unmount()
+  })
+
+  it('emits batchGenerate and closes the menu when "批量生成" is clicked', async () => {
+    const wrapper = mount(GenerateMenuButton, { attachTo: document.body })
+    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)
+    expect(wrapper.find('[data-testid="batch-generate"]').exists()).toBe(false)
+    wrapper.unmount()
+  })
+
+  it('closes the menu when clicking outside the component', async () => {
+    const wrapper = mount(GenerateMenuButton, { attachTo: document.body })
+    await wrapper.get('button[data-testid="generate-menu-toggle"]').trigger('click')
+    expect(wrapper.find('[data-testid="generate"]').exists()).toBe(true)
+
+    document.body.click()
+    await wrapper.vm.$nextTick()
+
+    expect(wrapper.find('[data-testid="generate"]').exists()).toBe(false)
+    wrapper.unmount()
+  })
+
+  it('closes the menu when Escape is pressed', async () => {
+    const wrapper = mount(GenerateMenuButton, { attachTo: document.body })
+    await wrapper.get('button[data-testid="generate-menu-toggle"]').trigger('click')
+    expect(wrapper.find('[data-testid="generate"]').exists()).toBe(true)
+
+    await wrapper.get('div.generate-menu').trigger('keydown', { key: 'Escape' })
+
+    expect(wrapper.find('[data-testid="generate"]').exists()).toBe(false)
+    wrapper.unmount()
+  })
+})