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/Cargo.toml

@@ -0,0 +1,41 @@
+[package]
+name = "oxide-engine"
+description = "Oxide 3D game engine — core library"
+version.workspace = true
+edition.workspace = true
+authors.workspace = true
+license.workspace = true
+rust-version.workspace = true
+
+[dependencies]
+glam.workspace = true
+hecs.workspace = true
+winit.workspace = true
+wgpu.workspace = true
+pollster.workspace = true
+bytemuck.workspace = true
+gltf.workspace = true
+ab_glyph.workspace = true
+log.workspace = true
+anyhow.workspace = true
+thiserror.workspace = true
+serde.workspace = true
+ron.workspace = true
+notify.workspace = true
+oxide-engine-derive = { path = "../engine-derive" }
+
+[dev-dependencies]
+env_logger.workspace = true
+criterion.workspace = true
+
+[[bench]]
+name = "transform"
+harness = false
+
+[[bench]]
+name = "scene"
+harness = false
+
+[[bench]]
+name = "app"
+harness = false