合并 AI 设计多会话客户端

整合 Enter 发送与多会话交互，保留服务端持久 Conversation Session，并补齐迁移、回归、Electron E2E 与 canonical 文档。

tests/e2e/image-workspace-conversations.spec.ts

@@ -0,0 +1,52 @@
+import { closeElectronApp, expect, getStableWindow, test } from './fixtures/electron';
+
+test.describe('AI Design conversations', () => {
+  test('keeps generation tasks visible while conversations stay independent', async ({ launchElectronApp }) => {
+    const app = await launchElectronApp({
+      imageWorkspaceMode: 'local',
+      skipSetup: true,
+    });
+
+    try {
+      const page = await getStableWindow(app);
+      await page.getByTestId('sidebar-module-switcher-trigger').click();
+      await page.getByTestId('sidebar-module-painting').click();
+
+      await page.getByTestId('sidebar-create-image-project').click();
+      await page.getByLabel('项目名称').fill('多会话验收项目');
+      await page.getByRole('button', { name: '创建项目' }).click();
+
+      const conversationSelect = page.getByTestId('image-canvas-conversation-select');
+      await expect(conversationSelect).toBeVisible();
+      await expect(conversationSelect.locator('option')).toHaveCount(1);
+      const firstConversationId = await conversationSelect.inputValue();
+
+      const firstPrompt = '为项目设计一张蓝色星空海报';
+      await page.getByLabel('设计需求').fill(firstPrompt);
+      await page.getByRole('button', { name: '发送给设计 Agent' }).click();
+      await expect(page.getByTestId('image-workspace-conversation')).toContainText(firstPrompt);
+      await page.getByRole('button', { name: '确认并开始生成' }).click();
+
+      const task = page.locator('[data-testid^="design-task-"]').first();
+      await expect(task).toContainText(firstPrompt);
+
+      await page.getByRole('button', { name: '新建设计会话' }).first().click();
+      await expect(conversationSelect.locator('option')).toHaveCount(2);
+      await expect(conversationSelect).not.toHaveValue(firstConversationId);
+      await expect(page.getByTestId('image-workspace-conversation')).not.toContainText(firstPrompt);
+      await expect(task).toContainText(firstPrompt);
+
+      const secondPrompt = '这一条会话只讨论红色角色立绘';
+      await page.getByLabel('设计需求').fill(secondPrompt);
+      await page.getByRole('button', { name: '发送给设计 Agent' }).click();
+      await expect(page.getByTestId('image-workspace-conversation')).toContainText(secondPrompt);
+
+      await conversationSelect.selectOption(firstConversationId);
+      await expect(page.getByTestId('image-workspace-conversation')).toContainText(firstPrompt);
+      await expect(page.getByTestId('image-workspace-conversation')).not.toContainText(secondPrompt);
+      await expect(task).toContainText(firstPrompt);
+    } finally {
+      await closeElectronApp(app);
+    }
+  });
+});