Import Oxide engine (Stages 0–10) under MIT license

Full project snapshot migrated to new Gitea remote without history:
engine, editor, physics, script, examples, tests, docs, and assets.
Relicensed from GPLv3 to MIT and updated repo URLs.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

engine/src/math/mod.rs

@@ -0,0 +1,39 @@
+//! Math and core geometric primitives.
+//!
+//! This module is the foundation every other Oxide system depends on. It builds
+//! on [`glam`] for vectors, quaternions, and matrices, and adds the engine's own
+//! higher-level types:
+//!
+//! - [`Transform`] — decomposed translation/rotation/scale, the unit of placement
+//! - [`Aabb`] — axis-aligned bounding box for bounds and culling
+//! - [`Ray`] — origin + direction, for picking and queries
+//! - [`Plane`] — infinite plane in Hessian normal form
+//! - [`Frustum`] — six-plane view volume for visibility culling
+//! - [`Color`] — linear RGBA color with sRGB conversion
+//! - [`Rect`] — 2D rectangle for UI and viewports
+//! - [`Range3`] — 3D value range for clamping and remapping
+//!
+//! `glam`'s own types are re-exported so downstream crates have a single import
+//! site for all math.
+
+mod aabb;
+mod color;
+mod frustum;
+mod plane;
+mod range3;
+mod ray;
+mod rect;
+mod transform;
+
+pub use aabb::Aabb;
+pub use color::Color;
+pub use frustum::Frustum;
+pub use plane::Plane;
+pub use range3::Range3;
+pub use ray::Ray;
+pub use rect::Rect;
+pub use transform::Transform;
+
+// Re-export the most commonly used `glam` types so consumers don't need a
+// separate dependency on `glam` for everyday math.
+pub use glam::{EulerRot, Mat3, Mat4, Quat, Vec2, Vec3, Vec4};