Add a local SvxReflector Docker lab for headset testing.

Funknetz needs a protocol 2.0 reflector without production credentials; the compose stack and smoke test prove the station can log in and select a talk group.

Co-authored-by: Cursor <cursoragent@cursor.com>

svxlink-docker/docker-compose.yml

@@ -0,0 +1,33 @@
+# Local SvxReflector lab for Funknetz.
+# Build once, then: docker compose up -d
+# Connect the app with host/port/callsign/authKey from .env (see FUNKNETZ_*).
+
+services:
+  svxreflector:
+    build:
+      context: .
+      dockerfile: Dockerfile
+      args:
+        GIT_URL: https://github.com/sm0svx/svxlink.git
+        GIT_BRANCH: master
+    image: funknetz-svxreflector:local
+    container_name: funknetz-svxreflector
+    restart: unless-stopped
+    env_file:
+      - .env
+    ports:
+      # Host LISTEN_PORT → container 5300 (must match config/svxreflector.conf).
+      # Control is TCP; audio and UDP keepalives use the same number.
+      - "${LISTEN_PORT:-5300}:5300/tcp"
+      - "${LISTEN_PORT:-5300}:5300/udp"
+    environment:
+      TZ: ${TZ:-Europe/Berlin}
+      START_SVXLINK: ${START_SVXLINK:-0}
+      START_REMOTETRX: ${START_REMOTETRX:-0}
+      START_SVXREFLECTOR: ${START_SVXREFLECTOR:-1}
+      SVXREFLECTOR_CONF: ${SVXREFLECTOR_CONF:-/etc/svxlink/svxreflector.conf}
+      SVXREFLECTOR_ARGS: ${SVXREFLECTOR_ARGS:-}
+    volumes:
+      - ./config/svxreflector.conf:/etc/svxlink/svxreflector.conf:ro
+      - ./logs:/var/log/svxlink
+      - ./data:/var/lib/svxlink