docker: expose metrics and internal API

DOCKER.md

@@ -8,3 +8,6 @@
 
 The Caddy server will listen on `localhost:5004` for the frontend and API,
 and on `localhost:5005` for the profile URL shortener.
+
+The backend server listens on `localhost:5006` for unproxied API access,
+and `localhost:5007` for metrics.

docker-compose.yml

@@ -9,7 +9,11 @@ services:
       - "Database:EnablePooling=true"
       - "Host=0.0.0.0"
       - "Port=5000"
+      - "Logging:MetricsPort=5001"
     restart: unless-stopped
+    ports:
+      - "5006:5000"
+      - "5007:5001"
     volumes:
       - ./docker/config.ini:/app/config.ini