SKILL.md parser and loader for Talos agent skills.

This crate discovers and parses SKILL.md files from configured search paths. Each skill consists of YAML frontmatter (between --- delimiters) followed by a Markdown body containing instructions.

Discovery Paths

Skills are discovered from three locations (in priority order):

1. .talos/skills/ — project-local skills
2. ~/.talos/skills/ — user-global skills
3. Parent directories up to git root — inherited skills

Directory-link following is controlled by SkillDiscoveryPolicy. By default links are not followed; external targets are denied. Discovery is bounded by the configured maximum depth and entry budget.

SKILL.md Format

---
name: my-skill
description: A skill that does something useful
triggers:
  - keyword1
  - keyword2
---

# Instructions

Detailed markdown instructions go here...