fix: bind Caddy to 0.0.0.0:8080 for external proxy access

Mac mini nginx proxies to GPU server Caddy. localhost-only binding
blocked external connections.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docker-compose.yml

@@ -90,7 +90,7 @@ services:
   caddy:
     image: caddy:2
     ports:
-      - "127.0.0.1:8080:80"
+      - "8080:80"
     volumes:
       - ./Caddyfile:/etc/caddy/Caddyfile
       - caddy_data:/data