Phase 0.63 style bundles

hedron_core.compile_style_bundle() provides a deterministic CSS artifact for the compatibility stylesheet or a selected component set. The scoped form is theme-aware and uses the same reset, token, accessibility, and state rules as the complete stylesheet.

For server asset registration, use style_bundle_asset_refs(). It returns local assets in dependency order: tokens.css, base.css, a11y.css, then the selected component files. The same /hedron-static directory is mounted by the FastAPI, Flask, Django, Posit, and static adapters, so registration does not require framework-specific CSS generation.

compare_style_bundle_sizes() is the release evidence check that confirms a component-scoped bundle is smaller than the complete compatibility asset. Applications should keep the complete stylesheet for compatibility and opt into scoped assets only when their component inventory is known.