Early UI work.

lib/ui/src/lib.rs

@@ -0,0 +1,26 @@
+//! Shared explicit-construction UI substrate for RUIN.
+//!
+//! This crate intentionally starts with explicit Rust data construction rather than a proc-macro
+//! authoring layer. The goal is to validate the threading, windowing, and scene handoff model
+//! before committing to ergonomic surface syntax. Concrete platform and renderer backends live in
+//! sibling crates.
+
+pub(crate) mod trace_targets {
+    pub const PLATFORM: &str = "ruin_ui::platform";
+    pub const SCENE: &str = "ruin_ui::scene";
+}
+
+mod platform;
+mod runtime;
+mod scene;
+mod window;
+
+pub use platform::{PlatformClosed, PlatformEvent, PlatformProxy, PlatformRuntime, start_headless};
+pub use runtime::{EventStreamClosed, UiRuntime, WindowController};
+pub use scene::{
+    Color, DisplayItem, GlyphInstance, Point, PreparedText, Quad, Rect, SceneSnapshot, Translation,
+    UiSize,
+};
+pub use window::{
+    DecorationMode, WindowConfigured, WindowId, WindowLifecycle, WindowSpec, WindowUpdate,
+};