On macOS/Linux the OS asserts DTR and RTS when the port is opened and
pyserial then writes DTR before RTS, passing through RTS=1/DTR=0 - the
USB-Serial-JTAG reset state. Every Connect restarted the box. Drop RTS
before open and DTR right after it on posix; Windows is unchanged.
Verified on macOS 27 / arm64 with box A4:CB:8F:C9:47:3C (fw 1.0.16,
build 3ae273ec): connect keeps the box running, Reset & capture still
restarts it.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
