Create and edit ERD Designer .erd files (database entity-relationship diagrams). Use when the user asks to design database tables, add or modify tables, columns, relations, indexes or memos in a .erd file, or to export DDL from a .erd file.
Generate and insert a new CHANGELOG.md version entry from git changes between main and the current branch. Use this skill whenever the user wants to update CHANGELOG.md, write release notes, document what changed since branching from main, or add a new version entry. Trigger on phrases like "update changelog", "add changelog entry", "document changes".