fix: hardcode nginx-k8s.conf in dashboard Dockerfile

The buildx plugin was not passing NGINX_CONF build arg correctly,
causing the docker-compose nginx config (with hostname api-gateway)
to be used instead of the K8s one (with localhost).

.woodpecker.yml

@@ -48,8 +48,6 @@ steps:
       repo: viktorbarzin/trading-bot-dashboard
       dockerfile: docker/Dockerfile.dashboard
       context: .
-      build_args:
-        - NGINX_CONF=docker/nginx-k8s.conf
       cache_from: viktorbarzin/trading-bot-dashboard:latest
       tags:
         - "${CI_PIPELINE_NUMBER}"

docker/Dockerfile.dashboard

@@ -23,9 +23,8 @@ FROM nginx:alpine
 # Remove default nginx site
 RUN rm /etc/nginx/conf.d/default.conf
 
-# Copy custom nginx config (override NGINX_CONF for K8s builds)
-ARG NGINX_CONF=docker/nginx.conf
-COPY ${NGINX_CONF} /etc/nginx/conf.d/default.conf
+# Copy K8s nginx config (api-gateway on localhost since they share a pod)
+COPY docker/nginx-k8s.conf /etc/nginx/conf.d/default.conf
 
 # Copy built assets from the builder stage
 COPY --from=builder /app/dist /usr/share/nginx/html