fix: Add cgroup rule for ttyACM devices (ESP32-S3)

ttyACM uses major 166, not 188 like ttyUSB.
Needed for Espressif ESP32-S3 based devices (Heltec V3, etc.)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

docker-compose.yml

@@ -6,10 +6,12 @@ services:
       dockerfile: Dockerfile
     container_name: meshcore-bridge
     restart: unless-stopped
-    # Grant access to all ttyUSB devices (major 188) for auto-detection
+    # Grant access to serial devices for auto-detection
     # This allows MC_SERIAL_PORT=auto to work without specifying device upfront
+    # Major 188 = ttyUSB (CP2102, CH340, etc.), Major 166 = ttyACM (ESP32-S3, etc.)
     device_cgroup_rules:
       - 'c 188:* rmw'
+      - 'c 166:* rmw'
     volumes:
       - "${MC_CONFIG_DIR}:/root/.config/meshcore:rw"
       - "/dev:/dev"