Tooling · Catalogs: token viewer, contrast audit; fg_subtle meets AA

DesignTokenViewer shows every token of the theme in the mode shown,
named as code reads it: colors with their hex, syntax, chart and
terminal colors, the type scale, radii, control and icon sizes,
elevations and spacing. A11yChecker audits each text color over the
surfaces it sits on at 4.5:1 and the focus ring and chart hues at
3:1, failures first. The audit found fg_subtle under 4.5:1 on hover
and overlay; it is #6f6d6a light and #8c8a87 dark now, and a test
holds all four Ely palettes to the audit. IconBrowser points to
forms::IconPicker and the ScreenshotTest Harness to the gallery's
capture, each with a section on the tooling page.

src/tooling/mod.rs

@@ -1,3 +1,4 @@
+mod a11y;
 mod events;
 #[cfg(debug_assertions)]
 mod inspector;
@@ -6,10 +7,13 @@ mod playground;
 mod renders;
 #[cfg(all(test, feature = "test-support"))]
 mod tests;
+mod tokens;
 
+pub use a11y::A11yChecker;
 pub use events::EventLogger;
 #[cfg(debug_assertions)]
 pub use inspector::install_inspector;
 pub use perf::FpsMeter;
 pub use playground::{Knob, Playground, Setting, Settings};
 pub use renders::RenderCounter;
+pub use tokens::DesignTokenViewer;