Problem

os.walk() does not follow symlinks by default. When a skill is installed via symlink (e.g., `ln -s /external/path skill`), the skill discovery system cannot find it because `iter_skill_index_files()` in agent/skill_utils.py uses `os.walk(skills_dir)` without `followlinks=True`.

This affects users who want to:

• Share skills across profiles via symlinks
• Keep skills in a separate directory outside `~/.hermes/skills/`
• Use the common pattern of symlinking skills from a codebase repository

Fix

Add `followlinks=True` to the `os.walk()` call in `iter_skill_index_files()`.

# Before
for root, dirs, files in os.walk(skills_dir):

# After
for root, dirs, files in os.walk(skills_dir, followlinks=True):

This is a minimal one-line change. Symlinks to `.git`, `.github`, and `.hub` directories are already filtered out by the existing `EXCLUDED_SKILL_DIRS` logic, so there is no security concern with following symlinks.