Add VS Code workspace/launch/settings for Unity development and a new MainMenu scene/UI (uxml, uss, tss) with MainMenuController and related assets. Import two alien character FBX models (with generated .meta settings) and add folder metadata. Update Git LFS pointers for a Game Kit scene and add modifications to Game Kit Controller assets (World Canvas material and Save Camera render texture) and ProjectSettings/QualitySettings. These changes bring initial UI/menu assets and character models into the project and add editor tooling/config for easier development.
Add a new Pause Menu UI (UXML, USS, TSS, asset/meta) and related UI folder metadata. Add new terrain assets and TerrainData files, plus lighting settings for the 2.5d demo scene. Import a new character model (X Bot.fbx) with its importer meta and new characters folder. Update SampleScene and LFS pointers, and refresh render pipeline settings (Mobile RP & URP global settings) and project/package settings. Tweak multiple material files: align _Color with BaseColor, add SHADOWCASTER to disabled shader passes for Ellen materials, and assign a missing main texture for Vincent_Hero_High_diffuse.
