v0.3.1 — Fix: repeat suppression could silence the call

Fixed

• Repeat suppression could silence the call (regression in 0.3.0, caught on
  real hardware): dropped audio wasn't communicated to the model, so when the
  other side asked it to repeat, the repeat was dropped again — the callee
  heard dead air until they hung up. Now the second occurrence plays (repeating
  once when asked is legitimate), from the third on the audio is dropped and
  the model is nudged to rephrase (8s cooldown); three consecutive suppressed
  repeats mark the call as stuck and end it politely instead of leaving
  silence.