Build multi-arch container images across stack
diff --git a/core/auth/ui/Dockerfile b/core/auth/ui/Dockerfile
index 8a76b08..980e40e 100644
--- a/core/auth/ui/Dockerfile
+++ b/core/auth/ui/Dockerfile
@@ -1,4 +1,6 @@
 FROM alpine:latest
 
-COPY server /usr/bin
+ARG TARGETARCH
+
+COPY server_${TARGETARCH} /usr/bin/server
 RUN chmod +x /usr/bin/server