/btw command fails with "Unknown skill: btw" in v2.1.76

Description

The /btw built-in command (introduced in v2.1.72) fails with Unknown skill: btw instead of opening the side-question overlay.

Steps to Reproduce

1. Start a Claude Code session
2. Type /btw testing at the prompt

Expected Behavior

A side-question overlay opens, showing the answer in context without entering conversation history.

Actual Behavior

Unknown skill: btw

Environment

• Claude Code version: 2.1.76
• OS: macOS Darwin 25.3.0

Notes

The error message says "Unknown skill" which suggests /btw is being routed through the skill lookup path rather than handled as a built-in command.