chore: Initial commit

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XPovRHpejR4zRxuhjY4Qs3

linux/runner/my_application.h

@@ -0,0 +1,18 @@
+#ifndef FLUTTER_MY_APPLICATION_H_
+#define FLUTTER_MY_APPLICATION_H_
+
+#include <gtk/gtk.h>
+
+G_DECLARE_FINAL_TYPE(MyApplication, my_application, MY, APPLICATION,
+                     GtkApplication)
+
+/**
+ * my_application_new:
+ *
+ * Creates a new Flutter-based application.
+ *
+ * Returns: a new #MyApplication.
+ */
+MyApplication* my_application_new();
+
+#endif  // FLUTTER_MY_APPLICATION_H_