fix: restore published port for myai-web + watchtower label

The docker-compose refactor moved port 5000:8080 to the override file.
Caddy on staging routes myai.easysoft.ro → localhost:5000, so the port
must be present in the deployment compose. Restoring it as WEB_PORT env var
(default 5000) and adding missing watchtower label.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docker-compose/docker-compose.yml

@@ -265,6 +265,8 @@ services:
     container_name: myai-web
     depends_on:
       - api
+    ports:
+      - "${WEB_PORT:-5000}:8080"
     environment:
       - ASPNETCORE_ENVIRONMENT=${ASPNETCORE_ENVIRONMENT:-Staging}
       - ASPNETCORE_URLS=${ASPNETCORE_URLS:-http://+:8080}
@@ -274,6 +276,8 @@ services:
     networks:
       - myai-network
     restart: unless-stopped
+    labels:
+      - "com.centurylinklabs.watchtower.enable=true"
 
 networks:
   myai-network: