build: Added just recipe for building the multi-platform image

justfile

@@ -23,3 +23,16 @@ fmt:
 [arg('build_type', pattern="debug|release")]
 build build_type='debug':
 	@cargo build {{ if build_type == "release" { "--release" } else { "" } }}
+
+# Build a multi-platform Docker image (linux/amd64 + linux/arm64).
+# Requires an active buildx builder with multi-platform support and a registry login.
+# version: must match an existing GitHub release tag (e.g. 0.7.4)
+# image:   registry/image name to push to (default: darkalex17/coyote)
+[group: 'build']
+docker-build version image='darkalex17/coyote':
+	docker buildx build \
+		--platform linux/amd64,linux/arm64 \
+		--build-arg COYOTE_VERSION={{ version }} \
+		--tag {{ image }}:{{ version }} \
+		--tag {{ image }}:latest \
+		.