Existing tools were either bloated or read-only. So I built Stash: push a Markdown file to Apple Notes, pull changes back. It uses YAML frontmatter to track which note belongs to which file.
Built with Bash, AppleScript, and Pandoc. No databases, no daemons, no config files. Install via Homebrew. Happy to take suggestions and answer questions about the quirks I ran into along the way.