[BUG] Slash Commands not found with Custom CLAUDE_CONFIG_DIR

Environment

• Platform (select one):
• [x] Anthropic API
• [ ] AWS Bedrock
• [ ] Google Vertex AI
• [ ] Other: <!-- specify -->
• Claude CLI version: 1.0.72 (Claude Code)
• Operating System: macOS Darwin 24.6.0
• Terminal: iTerm2

Bug Description

When using a custom CLAUDE_CONFIG_DIR environment variable, Claude Code doesn't properly discover global slash commands. It fails to look in $CLAUDE_CONFIG_DIR/.claude/commands/ as would be expected.

Steps to Reproduce

1. Set environment variable: export CLAUDE_CONFIG_DIR=~/GitHub/claude-config
2. Create slash commands in $CLAUDE_CONFIG_DIR/.claude/commands/
3. Start Claude Code session
4. Try to use custom slash commands (e.g., /ctx)
5. Commands are not found/available

Expected Behavior

Claude Code should check for slash commands in $CLAUDE_CONFIG_DIR/.claude/commands/ when CLAUDE_CONFIG_DIR is set, then fall back to ~/.claude/commands/ if not found.

Actual Behavior

Claude Code only checks ~/.claude/commands/ regardless of CLAUDE_CONFIG_DIR setting. Custom slash commands are not discovered.

Additional Context

Workaround currently in use:

# Create symlinks to make commands discoverable
ln -s $CLAUDE_CONFIG_DIR ~/.claude
ln -s .claude/commands $CLAUDE_CONFIG_DIR/commands

This allows Claude Code to find commands via the default ~/.claude path while keeping all configuration in the custom directory.

Impact: Without the workaround, custom slash commands are not available when using a custom config directory, affecting workflow automation and productivity.