[BUG] Skills don't receive IDE selection context (<ide_selection>) when invoked via slash command

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 invoking a custom skill via slash command in the VS Code extension, the skill does not receive the <ide_selection> context even when the user has code selected in their editor. The skill responds as if no selection exists and asks the user to specify a target manually.

The same <ide_selection> context IS visible in normal conversation turns — it's only missing when a skill is invoked.

What Should Happen?

Skills invoked via slash command should receive the same <ide_selection> and <ide_opened_file> context that's available in normal conversation. The skill prompt should be additive to the turn context, not replace it.

Error Messages/Logs

Steps to Reproduce

1. Open a file in VS Code and select some lines of code
2. In the Claude Code panel, type /skill-name (any custom skill that references IDE selection)
3. The skill executes but does not see the selected code
4. In contrast: type a normal message (not a slash command) with the same selection active — <ide_selection> is present in the context

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.31

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Other

Additional Information

I'm using the VSCode Claude extension v2.1.49. This issue has been opened and (wrongfully) auto-closed by the GH actions bot already: https://github.com/anthropics/claude-code/issues/6906