test(c-messages): add aimock e2e (Task #4 pilot slice)

First slice of Task #4 (aimock e2e for newly-eligible caps).
Generated via scripts/generate-aimock-scaffold.ts --cap c-messages,
with hand-authored fixture content and spec assertions.

- 5 new e2e/ files (playwright config + global-setup-impl + tsconfig
  + fixtures/c-messages.json + c-messages.spec.ts).
- project.json gains the e2e Nx target.
- ci.yml matrix gains a c-messages entry.

Two spec tests:
- user message + AI response both render via submitAndWaitForResponse.
- chat-message-list renders both turns (regression coverage for
  PR #466's primitive-demo fix).

The demo was broken at the component level in PR #462 (raw
ChatMessageListComponent without projected templates). PR #466 fixed
that by projecting the four chat-message templates. This re-pilot
verifies the aimock e2e against the fixed demo.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: blove

.github/workflows/ci.yml

@@ -270,6 +270,7 @@ jobs:
           - { angular: cockpit-chat-tool-calls-angular,     python: cockpit/chat/tool-calls/python }
           - { angular: cockpit-chat-subagents-angular,      python: cockpit/chat/subagents/python }
           - { angular: cockpit-chat-interrupts-angular,     python: cockpit/chat/interrupts/python }
+          - { angular: cockpit-chat-messages-angular,          python: cockpit/chat/messages/python }
     steps:
       - uses: actions/checkout@v6.0.2
       - uses: actions/setup-node@v6.3.0

cockpit/chat/messages/angular/e2e/c-messages.spec.ts

@@ -0,0 +1,23 @@
+// SPDX-License-Identifier: MIT
+import { test, expect } from '@playwright/test';
+import { submitAndWaitForResponse } from '../../../../../libs/e2e-harness/src';
+
+const PROMPT = 'Hello';
+
+test('c-messages: user message and AI response both render', async ({ page }) => {
+  const bubble = await submitAndWaitForResponse(page, PROMPT);
+
+  await expect(
+    page.locator('chat-message[data-role="user"]').last(),
+  ).toContainText(PROMPT);
+
+  await expect(bubble).toContainText('chat-messages capability demo');
+});
+
+test('c-messages: chat-message-list renders both turns', async ({ page }) => {
+  await submitAndWaitForResponse(page, PROMPT);
+
+  // Post-PR-#466 the demo projects user + assistant templates, so the
+  // list renders one bubble per message. Regression coverage for that fix.
+  await expect(page.locator('chat-message-list chat-message')).toHaveCount(2);
+});

cockpit/chat/messages/angular/e2e/fixtures/c-messages.json

@@ -0,0 +1,10 @@
+{
+  "fixtures": [
+    {
+      "match": { "userMessage": "Hello" },
+      "response": {
+        "content": "Hi! I'm the chat-messages capability demo. I show how ChatMessageListComponent, ChatInputComponent, and ChatTypingIndicatorComponent render together. Try sending a few messages to see the bubbles and typing indicator in action."
+      }
+    }
+  ]
+}

cockpit/chat/messages/angular/e2e/global-setup-impl.ts

@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: MIT
+import { resolve } from 'node:path';
+import { createGlobalSetup } from '../../../../../libs/e2e-harness/src';
+
+export default createGlobalSetup({
+  langgraphCwd: 'cockpit/chat/messages/python',
+  langgraphPort: 5501,
+  angularProject: 'cockpit-chat-messages-angular',
+  angularPort: 4501,
+  fixturesDir: resolve(__dirname, 'fixtures'),
+});

cockpit/chat/messages/angular/e2e/playwright.config.ts

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: MIT
+import { defineConfig, devices } from '@playwright/test';
+
+export default defineConfig({
+  testDir: '.',
+  testMatch: '**/*.spec.ts',
+  fullyParallel: false,
+  workers: 1,
+  retries: process.env.CI ? 2 : 0,
+  reporter: process.env.CI ? [['list'], ['html', { open: 'never' }]] : 'list',
+  use: {
+    baseURL: 'http://localhost:4501',
+    trace: 'retain-on-failure',
+  },
+  projects: [{ name: 'chromium', use: { ...devices['Desktop Chrome'] } }],
+  globalSetup: './global-setup-impl.ts',
+  globalTeardown: require.resolve('../../../../../libs/e2e-harness/src/global-teardown'),
+});

cockpit/chat/messages/angular/e2e/tsconfig.json

@@ -0,0 +1,14 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "ES2022",
+    "moduleResolution": "Bundler",
+    "esModuleInterop": true,
+    "strict": true,
+    "skipLibCheck": true,
+    "noEmit": true,
+    "types": ["node"]
+  },
+  "include": ["**/*.ts"],
+  "exclude": ["node_modules", "test-results", "playwright-report"]
+}

cockpit/chat/messages/angular/project.json

@@ -87,6 +87,12 @@
         "cwd": "cockpit/chat/messages/angular",
         "command": "npx tsx -e \"import { chatMessagesAngularModule } from './src/index.ts'; const module = chatMessagesAngularModule; if (module.id !== 'chat-messages-angular' || module.title !== 'Chat Messages (Angular)') { throw new Error('Unexpected module shape for ' + module.id); }\""
       }
+    },
+    "e2e": {
+      "executor": "@nx/playwright:playwright",
+      "options": {
+        "config": "cockpit/chat/messages/angular/e2e/playwright.config.ts"
+      }
     }
   }
 }