e2e: copilotkit-v2-voice-input 在本机稳定红——chat-mic-listening 15s 内不可见（main 基线可复现，与 #2033 无关）

2026-08-25 在 #2033 修复验证过程中发现，与该修复无关（voice-input spec 不使用 page.route）：

- \`apps/web/e2e/copilotkit-v2-voice-input.spec.ts:55\`：点击麦克风后 \`chat-mic-listening\` 15s 内不可见，用例红。
- **main 基线（449bef63）单跑同样红**，同一断言；#2033 分支 4 轮全套件 + 1 轮单跑也全红。全套件偶有绿（波动）。
- 失败层在真实 getUserMedia + ASR WS 握手（"正在听……"状态从未出现），疑与本机 ASR loopback/权限环境有关。

复现：
\`\`\`
pnpm exec tsx .harness/scripts/with-test-isolation.ts -- pnpm --filter web exec playwright test --config playwright.chat-read.config.ts copilotkit-v2-voice-input
\`\`\`

Start with apps/web/e2e/copilotkit-v2-voice-input.spec.ts:55 and run the supplied Playwright command against the main baseline. Trace the real getUserMedia and ASR WebSocket handshake to determine whether the failure is in the test or the local permissions/loopback environment. Done means the root cause and a reproducible resolution are established.

Written by the indexing model from the issue text.