Unify CSS-to-RN compiler and runtime pipeline

[cray0000]

Summary

This PR unifies the CSS-to-React-Native style pipeline into a new @cssxjs/css-to-rn workspace package and wires CSSX, loaders, Babel output, and runtime entrypoints through it. The goal is to replace the separate forked CSS-to-RN transform libraries and the old CSSX runtime with one maintainable compiler/runtime package.

Key changes:

• Adds packages/css-to-rn, a TypeScript ESM package owning CSS parsing, selector IR, value resolution, property transforms, style resolution, caching, and React runtime tracking.
• Keeps Stylus-to-CSS compilation separate, while moving pure CSS-to-RN style compilation and runtime resolution into the unified package.
• Supports local JS template interpolation in function-scoped css/styl templates, with interpolation values reusing one cache slot per compiled call shape.
• Adds runtime CSS string compilation for generated CSS via useCompiledCss(), useCssxLayer(), and cssx().
• Implements nested var() resolution, partial shorthand substitution, dynamic dependency tracking, bounded cache behavior, deep inline-style hashing, media/dimension tracking, web matchMedia invalidation, and React Native Dimensions integration.
• Adds React 19 useSyncExternalStore tracking without Teamplay or @nx-js/observer-util, including Suspense/aborted-render cleanup tests.
• Implements :hover/:active aliases, filter, background-image/gradient support, limited background shorthand, animations/transitions/keyframes, and Reanimated v4-compatible animation style output.
• Adds build-strict diagnostics for unsupported static declarations while keeping runtime compilation graceful for generated CSS.
• Migrates loaders and Babel runtime paths to the unified package, with source-condition test/dev imports and built/default import smoke coverage.
• Stops tracking generated dist output; package builds still emit dist for published/default exports.
• Keeps legacy runtime/*-teamplay import paths as compatibility wrappers only.
• Removes the old packages/runtime package from the active graph.
• Updates architecture.md, AGENTS.md, plan.md, public docs, README credits, and CI smoke checks for the new architecture.

Validation

• cd packages/css-to-rn && npm test
• cd packages/css-to-rn && npm run build
• source-condition import smoke with node -C cssx-ts
• built/default package import smoke after local build
• CI=true yarn test
• yarn docs-build
• git diff --check
• GitHub Actions PR check is passing on the latest commit.

Review Focus

This is a large architectural PR. Please scrutinize:

• Runtime cache invalidation, interpolation cache behavior, and reference stability.
• Media/dimension invalidation, web matchMedia subscriptions, React Native dimensions, and listener cleanup.
• Suspense/aborted-render subscription safety and memory leak edge cases.
• Complex value parsing: nested var(), shorthand fragments, gradients/backgrounds, transforms, animations, transitions, and invalid generated CSS.
• Babel output compatibility with existing CSSX styleName, css, styl, and part workflows.
• Package exports/source-condition behavior and whether the new package boundary is maintainable long term.