Add MQTT-based STT worker for VAD segments

bridge/.env.example

@@ -33,3 +33,14 @@ VAD_POSTROLL_MS=1000
 VAD_START_THRESHOLD=900
 VAD_STOP_THRESHOLD=600
 VAD_MIN_SPEECH_MS=300
+
+# STT worker settings (faster-whisper)
+MQTT_VAD_TOPIC=evs/+/vad_segment
+MQTT_TRANSCRIPT_TOPIC_TEMPLATE=evs/{device_id}/transcript
+MQTT_STT_ERROR_TOPIC_TEMPLATE=evs/{device_id}/stt_error
+STT_MODEL=small
+STT_DEVICE=cpu
+STT_COMPUTE_TYPE=int8
+STT_BEAM_SIZE=1
+STT_LANGUAGE=de
+STT_CONDITION_ON_PREV_TEXT=false