Login web View issue

2025-10-24 13:14:08.521 [error] notifications: Failed to fetch at endpoint: https://idetoolkits-hostedfiles.amazonaws.com/Notifications/VSCode/startup/1.x.json, err: TypeError: Cannot read properties of undefined (reading 'headers')
2025-10-24 13:14:10.649 [error] API response (oidc.us-east-1.amazonaws.com /client/register): { name: 'TimeoutError' }
2025-10-24 13:14:10.657 [error] ssoSetup encountered an error: Error: Failed to connect to AWS Builder ID [FailedToConnect]
-> TimeoutError: Connection timed out after 12000 ms
2025-10-24 13:14:10.657 [error] webviewId="aws.amazonq.AmazonCommonAuth": Error: Webview error
-> Error: Webview backend command failed: "startCodeWhispererBuilderIdSetup()"
-> Error: Failed to connect to AWS Builder ID [FailedToConnect]
-> TimeoutError: Connection timed out after 12000 ms
2025-10-24 13:14:10.657 [warning] telemetry: invalid Metric: "auth_addConnection" emitted with missing fields: featureId,isAggregated

Start with the logged webview entry point `startCodeWhispererBuilderIdSetup()` and the `amazonCommonAuth` webview error, then trace the failed AWS Builder ID connection and OIDC client registration timeout. Reproduce the login flow and inspect the related authentication path; done means the Builder ID setup no longer fails with the reported webview error.

Written by the indexing model from the issue text.