feat: add compile-time raw color helpers

[e-simpson]

Summary

Adds compile-time helpers for React Native APIs that need raw color strings rather than style objects:

const blue = twColor`blue-500`;
const tint = useTwColor("scheme:accent");
const colors = useTwColors({
  background: "scheme:background",
  text: "scheme:text",
  accent: "blue-500/[.37]",
});

• twColor resolves one static module- or component-scope token with zero runtime work and rejects scheme:.
• useTwColor() and useTwColors() resolve reactive scheme colors with the Babel plugin's configured custom or native theme hook.
• Palette names, utility-form names, integer/arbitrary opacity, arbitrary hex, and outline colors share the parser's color grammar.
• Calls compile to string literals and conditional expressions with no runtime Tailwind lookup.

Dependency / merge order

Please merge #14, then #15, then #18.

This draft is intentionally stacked on #14 and #15 so raw colors are already verified with arbitrary opacity and scheme:outline-*. Until those PRs land, GitHub shows their commits here; the base diff reduces after each dependency merges.

Static and reactive contracts

• Static twColor accepts one interpolation-free token and rejects runtime scheme: with an error directing callers to useTwColor.
• Reactive helpers require direct static calls inside function components.
• Unknown tokens, dynamic expressions, module-scope hooks, and rebinding compile-only helpers fail during Babel transformation.
• Scheme hooks are injected before React Compiler analysis.

Type checking

The Babel plugin validates tokens against the actual consumer Tailwind config. Since a package declaration cannot automatically infer another project's Babel-loaded config, the base TypeScript signature remains string.

Applications can retain config-derived autocomplete and typo checking without wrappers:

type ThemeColor = keyof typeof tailwindConfig.theme.extend.colors;
type SchemeThemeColor = `scheme:${ThemeColor}`;

const card = useTwColor("scheme:card" satisfies SchemeThemeColor);

The compiler now unwraps satisfies, as, and type-assertion expressions around direct literals before compiling them.

Validation

• bun run spec — 1,096 passed, 1 skipped
• bun run check
• bun run lint
• bun run format:check
• bun run build
• git diff --check