test(web): pin the subagent snapshot to English

The subagent conversation scenario asserts English role names and compares English accessibility goldens, but it opened a raw Playwright page while the rest of the English Web scenarios use the shared bootstrap that writes dsh.locale before client initialization. Once the subagent surface became localized, the raw page left those assertions dependent on ambient browser or persisted locale selection.

Create the page through newEnglishPage so the product sees an explicit English preference before boot, while preserving the standard 1680 by 1000 viewport. Chinese-surface scenarios continue to bypass this helper and advertise their own locale explicitly.

A fresh library build and production Vite build completed successfully. The focused assembled subagent-conversation Web suite then passed all 8 keyless replay tests against the updated singular-copy golden, and the staged diff passes formatting, lint, and whitespace hooks.

apps/web/tests/subagent-conversation.e2e.ts

@@ -15,7 +15,7 @@ import {
   launchWebScaffold, watchConsole,
   webSnapshotMode, type WebScaffold,
 } from './scaffold.ts'
-import { connectFreshWorkspace, saveFailureShot } from './support.ts'
+import { connectFreshWorkspace, newEnglishPage, saveFailureShot } from './support.ts'
 
 const BASE_FIXTURE = fileURLToPath(new URL('./snapshots/live-interactions/session.jsonl', import.meta.url))
 const AVAILABLE_CHILD_EXPECTED = fileURLToPath(new URL('./snapshots/subagent-conversation/ui.expected.md', import.meta.url))
@@ -77,7 +77,7 @@ describe('web e2e: persisted subagent conversation and human continuation', () =
       paceMs: 25,
     })
     browser = await chromium.launch()
-    page = await browser.newPage({ viewport: { width: 1680, height: 1000 } })
+    page = await newEnglishPage(browser)
     page.on('request', (request) => {
       const path = new URL(request.url()).pathname
       if (path.startsWith('/api/')) apiCalls.push(path)