[Bug] `/btw` command unavailable in VS Code extension due to missing `sendControlRequest` transport handler

Bug Description
/btw is unavailable in the VS Code extension but works in the terminal CLI on the same version (2.1.159). Repro: 1. VS Code extension (anthropic.claude-code-2.1.159-darwin-arm64): type "/" → /btw is absent; /btw <question> isn't recognized. 2. Terminal claude 2.1.159: /btw appears and works. Expected: /btw available in the extension too. Likely cause (from inspecting the bundle): /btw dispatches a side_question via sendControlRequest, and the extension transport appears to hit the "sendControlRequest not yet wired for <transport> transport" fallback — so control-request commands like /btw aren't exposed in the extension. Env: macOS (Darwin 25.5.0), arm64.

Environment Info

• Platform: darwin
• Terminal: Apple_Terminal
• Version: 2.1.159
• Feedback ID: aea9c2c3-baf4-41c1-9838-bc51cc213706

Errors

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