Describe the bug

Claude Code supports a custom location for settings instead of ~/.claude, via the CLAUDE_CONFIG_DIR environment variable. When installing a skill, gh skill ignores that variable and hardcodes ~/.claude instead for user-level installation, which results in the installed skills being ignored by Claude Code.

Affected version

gh version 2.91.0 (2026-04-22)
https://github.com/cli/cli/releases/tag/v2.91.0

Steps to reproduce the behavior

1. Install a skill

   gh skill install anthropics/skills \
       algorithmic-art@b9e19e6f44773509fbdd7001d77ff41a49a486c1 \
       --agent claude-code --scope user

2. Try to use the skill

   $ claude -p '/algorithmic-art'
   Unknown command: /algorithmic-art

Expected vs actual behavior

I expect the skill to be installed in $CLAUDE_CONFIG_DIR/skills, which defaults to ~/.claude/skills if $CLAUDE_CONFIG_DIR is not set.

Actual behaviour: skills are always installed in ~/.claude/skills.

Logs

$ env | grep CLAUDE_CONFIG_DIR
CLAUDE_CONFIG_DIR=/home/benjamin/.config/claude
$ GH_DEBUG=true gh skill install anthropics/skills algorithmic-art@b9e19e6f44773509fbdd7001d77ff41a49a486c1 --agent claude-code --scope user
Resolving version ⣾* Request at 2026-04-22 11:27:09.484835979 -0700 PDT m=+0.025141067

-->8-- snip

✓ Installed algorithmic-art (from anthropics/skills@b9e19e6f44773509fbdd7001d77ff41a49a486c1) in .claude/skills

-->8-- snip