supports binary-format, only esp* supported for now

internal/firmware/ext.go

@@ -0,0 +1,12 @@
+package firmware
+
+import "strings"
+
+// BinaryExt returns the binary file extension based on the binary format
+// Returns ".bin" for ESP-based formats, "" for others
+func BinaryExt(binaryFormat string) string {
+	if strings.HasPrefix(binaryFormat, "esp") {
+		return ".bin"
+	}
+	return ""
+}