Duplicate skills when home == repo root

When home directory is also the git repo root, Claude Code's skill discovery lists each skill twice in <available_skills>—once labeled as personal and once as project, despite both pointing to identical files.

Setup:

• Home directory IS the git repo (~ = dotfiles repo root)
• Skills stored in ~/.claude/skills/ (symlinks to submodule)
• .claude/skills/ and ~/.claude/skills/ are the same directory

Expected: Each unique SKILL.md file appears once in available skills list.

Actual: Each skill appears twice with different location labels, despite identical inode.

Suggested Fix: Deduplicate project/user configuration by checking samefile(). When personal and project skill paths resolve identically, keep only one entry.