Onboarding · Flows and highlights: wizard, hotspot, highlight, setup checklist

OnboardingWizard runs a first run on navigation::Wizard without its
numbered steps: "Step 2 of 4" over a bar in as many parts, the step's
title, line and content, Back and Next once ready, Finish last, and
Skip for now. Hotspot pulses on a dot that opens a tip on a press or
Enter, with Got it. FeatureHighlight names something new under a New
badge, with Try it and Not now, and rises in. SetupChecklist counts
first things to do in words and a bar, offers Start on each left, eases
a check in as one gets done, and offers Hide once all are.

navigation::Wizard now keys its buttons, steps and motion by its own id
and takes on_step and on_finish at render, failing loud without them.

src/theme/mod.rs

@@ -6,6 +6,7 @@ mod files;
 mod generative;
 mod media;
 mod messaging;
+mod onboarding;
 mod palette;
 mod project;
 mod tokens;
@@ -23,6 +24,7 @@ pub use files::FileSizes;
 pub use generative::GenerativeSizes;
 pub use media::MediaSizes;
 pub use messaging::MessagingSizes;
+pub use onboarding::OnboardingSizes;
 pub use palette::{HUE_NAMES, Mix, Palette, Syntax};
 pub use project::ProjectSizes;
 pub use tokens::{