fix: add port 8080 to Traefik dashboard service

Added loadbalancer.server.port=8080 to dashboard configuration
since the Traefik API/dashboard runs on port 8080 internally.

Also added ping endpoint for healthchecks.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

proxy/compose.yaml

@@ -8,6 +8,9 @@ services:
       - '--api.dashboard=true'
       - '--api.insecure=false'
 
+      # Ping endpoint for healthcheck
+      - '--ping=true'
+
       # Logging
       - '--log.level=${PROXY_LOG_LEVEL:-INFO}'
       - '--accesslog=true'
@@ -76,6 +79,7 @@ services:
       - 'traefik.http.routers.${PROXY_COMPOSE_PROJECT_NAME}-web-secure.service=api@internal'
       - 'traefik.http.middlewares.${PROXY_COMPOSE_PROJECT_NAME}-auth.basicauth.users=${PROXY_AUTH_USERS}'
       - 'traefik.http.routers.${PROXY_COMPOSE_PROJECT_NAME}-web-secure.middlewares=${PROXY_COMPOSE_PROJECT_NAME}-auth'
+      - 'traefik.http.services.${PROXY_COMPOSE_PROJECT_NAME}-web-secure.loadbalancer.server.port=8080'
       - 'traefik.docker.network=${NETWORK_NAME}'
 volumes:
   letsencrypt_data: