refactor(gameplay): replace entt components with SparseVector for player data

Refactor client world to use a custom SparseVector for player data instead of entt registry. Consolidate Transform, ViewAngles, and related structs into Position, Orientation, WalkPose. Introduce PlayerData and PlayerRenderData. Remove the unused move_system.cpp. Unify player render and shadow render into a single function.

src/CMakeLists.txt

@@ -96,6 +96,5 @@ target_sources(${PROJECT_NAME}
         render/model_manager.cpp
         render/model_renderer.cpp
         gameplay/chunk.cpp
-        gameplay/move_system.cpp
         gameplay/hitbox_manager.cpp
 )