Add start/stop tones and rotate WAV sessions

bridge/README.md

@@ -80,6 +80,10 @@ You can build automations on these events (for STT/TTS pipelines or Node-RED han
 
 - Audio format: PCM16LE, mono, 16 kHz
 - `SAVE_SESSIONS=true` stores `.wav` files in `bridge/data/sessions`
+- Recording is written during `start`..`stop` and rotated automatically:
+  - `WAV_SEGMENT_MAX_BYTES` max size per `.wav` file (default: `2097152` = 2 MB)
+  - `WAV_KEEP_FILES` max number of `.wav` files to keep (default: `10`)
+- `MAX_SESSION_BYTES` is only used if session file saving is disabled
 - MQTT is recommended for control/events, WebSocket for streaming audio
 
 ## 7) Build and push to Gitea registry
@@ -127,6 +131,8 @@ services:
       SAVE_SESSIONS: "true"
       SESSIONS_DIR: "/data/sessions"
       PCM_SAMPLE_RATE: "16000"
+      WAV_SEGMENT_MAX_BYTES: "2097152"
+      WAV_KEEP_FILES: "10"
     volumes:
       - evs_bridge_data:/data