Bump to v1.3.1

Finalize changelog for v1.3.0 release

Update .gitignore with codemunch, editor, and OS entries

Add settings.local.json and .DS_Store to .gitignore

Add release checklist, changelog, and bump to v1.3.0

autoimprove(004): Add gh/timeout guards to sessionstart hook for portability

autoimprove(003): Add jq availability guard to pretooluse hook

autoimprove(001): Replace echo-pipe patterns with herestrings and input redirection

Add upgrade instructions for users with stale installs

Merge pull request #3 from benmarte/feat/stderr-update-notification

Add stderr notification for update checks

Merge pull request #2 from benmarte/feat/upgrade-command

Add /codemunch:upgrade command and SessionStart update check

Merge branch 'feat/pretooluse-hook-docs'

Add /codemunch:disable and /codemunch:enable commands