Initial commit: project scaffold and kernel contract v0

Lay out the design that everything else builds on: a small frozen
kernel plugins treat as a shared language, the plugin contract, the
two-assembly hot-reload model, and the build order through M4.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N1qPfzq8TDCUMFMV3UwV5N

README.md

@@ -0,0 +1,28 @@
+# Lingua Engine
+
+A modular, plugin-first game engine built around one idea: the kernel is a
+shared language, not a shared implementation. Everything the engine can do —
+rendering, physics, audio, even the editor itself — is a plugin that speaks
+that language. The kernel only defines the vocabulary plugins use to
+understand each other.
+
+Built for Linux and Windows, in C#/.NET, with two goals that shape every
+design decision:
+
+- **Fast iteration.** No Unity-style domain reload. Plugins hot-reload their
+  compiled code without resetting game state, because state never lives in
+  plugin code to begin with — see [`docs/kernel-contract.md`](docs/kernel-contract.md).
+- **A small, frozen kernel.** Everything else — including the parts most
+  engines treat as core — is a plugin, versioned and replaceable per project.
+
+## Status
+
+Pre-implementation. The current design is written up in
+[`docs/kernel-contract.md`](docs/kernel-contract.md): what belongs in the
+kernel, the plugin contract, the hot-reload model, and the build order
+(M0–M4). Nothing has shipped yet — this document is the thing to argue with
+before code gets written.
+
+## License
+
+[MIT](LICENSE)