use named serial ports

Author: noahp

ai/AGENTS.md

@@ -5,3 +5,4 @@
 - Always use `rg` (ripgrep) instead of `grep` for searching file contents.
 - Always use `fd` instead of `find` for searching files and directories.
 - Always use the `gh` CLI when accessing or operating on GitHub resources (PRs, issues, releases, etc.).
+- When accessing serial ports, ALWAYS use named ports via `/dev/serial/by-id` (Linux — not macOS-style `/dev/tty.usbserial-*` paths).