Timetables have no GameScript API surface, so this implements real
DoCommands over the game port (ClientCommand/ServerCommand) instead of
the Admin GameScript relay used for list_vehicles(): change_timetable(),
autofill_timetable(), set_timetable_start(), and set_vehicle_on_time()
send commands, while get_vehicle_timetable() reconstructs state purely
by observing ServerCommand broadcasts, since no query command exists.
Includes the custom varuint wire codec these commands require, a full
usage guide (docs/TIMETABLES.md), and a worked demo in main.py.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
