a5f6475603
Implements the Agent Skills specification (https://agentskills.io) for portable skill packages that give the agent new capabilities. Changes: - Add skills module with SKILL.md parser (YAML frontmatter + markdown body) - Implement skill discovery from ~/.g3/skills/, config extra_paths, and .g3/skills/ - Generate <available_skills> XML for system prompt injection - Add SkillsConfig to g3-config with enabled flag and extra_paths - Wire skills discovery into CLI startup - Add 29 unit tests for parser, discovery, and prompt generation - Update README with Agent Skills documentation Skill locations (priority order): 1. ~/.g3/skills/ (global) 2. Config extra_paths 3. .g3/skills/ (workspace, highest priority) At startup, g3 scans skill directories and injects a summary into the system prompt. When the agent needs a skill, it reads the full SKILL.md using the read_file tool.