ports/RetroBIOS runs install.py on a handheld with PortMaster's own
screens (pugwash fifo_control through PortMasterDialog.txt), using only
what PortMaster 2024.02.26 and the 8.5.23 copy JELOS ships. It reads the
installer through --events. scripts/build_port.py writes RetroBIOS.zip
in the layout PortMaster's release build gives a port, with the
install.py the bootstraps pin, reproducibly. tests/test_port drives the
screens with stubbed dialog functions and a fake installer.
