Initial release of the self-improvement skill for structured learnings and error logging.

• Enables agents to capture learnings, corrections, errors, and feature requests in dedicated markdown files under .learnings/.
• Provides clear logging templates and category/tag structure for learnings, errors, and feature requests.
• Outlines criteria for promoting broadly relevant learnings to persistent project memory files (CLAUDE.md, AGENTS.md).
• Includes guidelines for recurring pattern detection, priority assignments, and periodic review practices.
• Offers quick reference tables, command examples, and review scripts to streamline adoption.
• Designed to support continuous improvement and reduce repeat mistakes.