Add PPI layer metadata save automation

src/assets/ppi_header.h

@@ -127,10 +127,18 @@ struct PpiDirtyFacePayloadConfig {
     std::span<const std::byte> png_rgba8;
 };
 
+struct PpiLayerMetadataConfig {
+    float opacity = 1.0F;
+    std::uint32_t blend_mode = 0;
+    bool alpha_locked = false;
+    bool visible = true;
+};
+
 struct PpiMinimalProjectConfig {
     std::uint32_t width = 0;
     std::uint32_t height = 0;
     std::string layer_name;
+    PpiLayerMetadataConfig layer_metadata;
     std::uint32_t layer_count = 1;
     std::uint32_t frame_count = 1;
     std::uint32_t frame_duration_ms = 100;