feat(verify): add universal --ground-truth verification against go tool asm

Assisted-by: Qwen 3.8 Max Preview

verify/verify.go

@@ -120,3 +120,8 @@ func (k *Kernel) Close() {
 		k.exec.Unmap()
 	}
 }
+
+// Image returns the assembled image (code + data + metadata).
+func (k *Kernel) Image() *asm.Image {
+	return k.img
+}