Start listening for expected follow-ups

Propagate the master's follow-up decision to slave devices and skip wake-word detection for one turn after response playback.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

javis-slave/README.md

@@ -27,6 +27,8 @@ screen (GUI mode) and played back through the device's speakers.
 4. **Turns** — After the wake word, the utterance is recorded locally
    (Silero VAD or RMS end-pointing), uploaded as WAV to `POST /api/v1/turn`,
    and the master's reply text + synthesized speech are returned and played.
+   When the master marks a reply as expecting a follow-up, the slave starts
+   listening immediately after playback without requiring another wake word.
    If the master's turn fails it returns its spoken error phrase instead, so a
    screenless satellite still gets audible feedback; connection problems play
    a low falling tone.