[BUG] Regression in 2.1.72 (VS Code, Bedrock): `400 tools.0.custom.eager_input_streaming: Extra inputs are not permitted`

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

When using Claude Code via Amazon Bedrock in VS Code, every request fails in extension version 2.1.72 with:
API Error: 400 tools.0.custom.eager_input_streaming: Extra inputs are not permitted

The error occurs immediately on any prompt (e.g., sending "Hi").

Downgrading to 2.1.71 resolves the issue completely.
Re-upgrading to 2.1.72 reproduces the failure immediately.

No configuration changes were made between versions.

Backend is Amazon Bedrock using AWS SSO profile authentication.

What Should Happen?

Claude Code should successfully process prompts via Amazon Bedrock, as it does in version 2.1.71.

Upgrading from 2.1.71 to 2.1.72 should not introduce a breaking change for Bedrock users.

Error Messages/Logs

`[ERROR] API error: 400 tools.0.custom.eager_input_streaming: Extra inputs are not permitted`

Additional context:
- Backend: Amazon Bedrock
- Region: us-east-1
- AWS SSO profile authentication
- CLI works
- 2.1.71 works
- 2.1.72 fails consistently

Attempted mitigation:
- Setting `CLAUDE_CODE_DISABLE_FINE_GRAINED_TOOL_STREAMING=1` did not resolve the issue in 2.1.72.

Steps to Reproduce

1. Use Claude Code in VS Code configured for Amazon Bedrock (AWS SSO profile).
2. Install extension version 2.1.72.
3. Send any prompt (e.g., "Hi").
4. Observe error: 400 tools.0.custom.eager_input_streaming: Extra inputs are not permitted
5. Downgrade extension to 2.1.71.
6. Repeat prompt.
7. Observe that it works normally.

Regression confirmed between 2.1.71 (working) and 2.1.72 (failing).

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.1.71

Claude Code Version

2.1.72

Platform

AWS Bedrock

Operating System

Windows

Terminal/Shell

VS Code integrated terminal

Additional Information

_No response_