fix: resolve heredoc parsing error in deploy-oci Makefile target

Extract inline Dockerfile to Dockerfile.oci and scp it instead of
generating it via heredoc over SSH. Make's line-continuation backslash
was causing the heredoc delimiter to be parsed as 'DEOFnFROM' by the
remote shell, breaking the image build step.

Dockerfile.oci

@@ -0,0 +1,9 @@
+FROM alpine:3.21
+RUN apk add --no-cache git ca-certificates
+WORKDIR /app
+COPY repo-vis-server ./
+COPY dist ./web/dist/
+ENV PORT=8080
+ENV FRONTEND_DIR=./web/dist
+EXPOSE 8080
+CMD ["./repo-vis-server"]

Makefile

@@ -39,18 +39,9 @@ deploy-oci: build-arm
 	ssh $(OCI_HOST) "rm -rf $(OCI_TMP) && mkdir -p $(OCI_TMP)"
 	scp server/target/$(MUSL_TARGET_ARM)/release/repo-vis-server $(OCI_HOST):$(OCI_TMP)/
 	cd web && tar czf /tmp/_rv_dist.tar.gz dist && scp /tmp/_rv_dist.tar.gz $(OCI_HOST):$(OCI_TMP)/
+	scp Dockerfile.oci $(OCI_HOST):$(OCI_TMP)/Dockerfile
 	@echo "==> Building image on OCI..."
-	ssh $(OCI_HOST) 'cd $(OCI_TMP) && tar xzf _rv_dist.tar.gz && cat > Dockerfile <<DEOF\n\
+	ssh $(OCI_HOST) 'cd $(OCI_TMP) && tar xzf _rv_dist.tar.gz && \
-FROM alpine:3.21\n\
-RUN apk add --no-cache git ca-certificates\n\
-WORKDIR /app\n\
-COPY repo-vis-server ./\n\
-COPY dist ./web/dist/\n\
-ENV PORT=8080\n\
-ENV FRONTEND_DIR=./web/dist\n\
-EXPOSE 8080\n\
-CMD ["./repo-vis-server"]\n\
-DEOF\n\
 sudo docker build -t repo-vis:latest . && \
 sudo docker save repo-vis:latest -o /tmp/_rv.tar && \
 sudo k3s ctr images import /tmp/_rv.tar'