refactor: restructure skills directory and improve error-handling skill

chore: update .claude-plugin

delete: duplicated files

feat: add Claude plugin package structure

feat: add per-skill installs and Claude skills path

docs: expand skill guides and references

docs: list all available skills

feat: expand skills catalog and refresh README

feat(ty-check): add TODO list workflow for systematic error fixing

feat(commands): add ty-check command for Cursor and Claude

fix(claude): use .shared/ for consistent skills across all IDEs

feat(claude): install skills to .claude/skills/ directory

chore: bump version to 0.1.3.4

feat(cli): add ty-skills to available skills list

chore: minor updates to commit-message script and dependencies