nginx: extra_hosts host-gateway for vite HMR upstream; gitignore root .env

nginx config has static upstream pointing at host.docker.internal:5173 for
Vite dev server. Without extra_hosts the DNS lookup fails at nginx startup
and crashes the container. Added back, harmless in prod (upstream just unused).

.gitignore

@@ -17,3 +17,8 @@ app/node_modules/
 app/vendor/
 app/public/build/
 app/public/hot
+
+# Compose stack env (contains secrets)
+/.env
+/.env.local
+

docker-compose.yml

@@ -48,6 +48,8 @@ services:
     restart: unless-stopped
     ports:
       - "${HTTP_PORT:-80}:80"
+    extra_hosts:
+      - "host.docker.internal:host-gateway"
     depends_on:
       app:
         condition: service_started