chore: sync from fn-registry agent

sokol_impl.cpp

@@ -0,0 +1,14 @@
+// Dedicated TU for sokol_gfx implementation. Including sokol_gfx.h with
+// SOKOL_IMPL elsewhere (e.g. main.cpp) plus then including any other header
+// that re-includes sokol_gfx.h re-emits the impl block — link/compile errors.
+//
+// Convention: this is the ONLY file in this app that defines SOKOL_IMPL.
+
+#define SOKOL_IMPL
+#if defined(__EMSCRIPTEN__)
+    #define SOKOL_GLES3
+#else
+    #define SOKOL_GLCORE
+#endif
+#include "sokol_gfx.h"
+#include "sokol_log.h"