Phase 1: Asset System Foundation - Task Breakdown

[Deliverooo]

Break down the initial Asset System implementation into actionable tasks:

1. Define AssetID (GUID/UUID) and AssetHandle types for all assets (meshes, materials, textures, shaders, etc).
2. Refactor MaterialSystem and other subsystems to use AssetID for identity (replace string-based lookups).
3. Implement AssetRegistry (mapping AssetID <-> source path <-> asset type) as a persistent database (JSON/YAML).
4. Design and implement .tmeta sidecar files for import metadata, hash, and dependencies.
5. Implement a basic import/cook pipeline for assets (Mesh, Texture, Material, Shader) to produce cooked binaries (.tmesh, .ttex, .tmat, .tshd) and store in a cache directory by GUID.
6. Create AssetManager: supports load/unload by GUID, reference counting, and fallback resources (default mesh, material, texture).
7. Add async asset loading: IO thread parses/cooks, render thread creates GPU resources, swap handles atomically.
8. Implement hot-reload: file watcher invalidates cache and reloads assets, with atomic swap of handles.

Each task should be completed and tested individually before moving to the next.