The two commands carried near-identical copies of fetch-until-short, split-at-a-natural-break and two-part send. modules/joke_text.py now holds them as plain functions (a mixin module under modules/commands would be loaded as a plugin and recorded as a failure). Each command keeps its public method names, its emoji, its own split points (joke also splits on newlines) and its own pause: joke still waits 2 s between the two parts, dadjoke does not. Lengths stay counted in characters against 130, as before.
