refactor: multi format generation and llgo build flags

internal/firmware/env.go

@@ -0,0 +1,16 @@
+package firmware
+
+import "strings"
+
+// BinaryFormatToEnvName returns the environment variable name based on the binary format
+// Returns the format name for template expansion (e.g., "bin", "uf2", "zip")
+func BinaryFormatToEnvName(binaryFormat string) string {
+	if strings.HasPrefix(binaryFormat, "esp") {
+		return "bin"
+	} else if strings.HasPrefix(binaryFormat, "uf2") {
+		return "uf2"
+	} else if strings.HasPrefix(binaryFormat, "nrf-dfu") {
+		return "zip"
+	}
+	return ""
+}