feat: expose compiled visually hidden text primitives

[0thernet]

Summary

Expose VisuallyHidden through the public package so consumers can preserve native text, document headings and live status semantics with the existing compiled StyleX recipe. The retired CSS hook is not restored.

• One native span, div, p or heading element; native attributes and refs remain on that element.
• Reuse the exact 15 important hiding atoms, keeping the stable hook before them and caller classes afterward. No injected hiding styles, runtime CSS or new dependency.
• Add public types, server-rendered semantics, packed React 18/19 probes and native gallery regressions for headings, live status updates and long labels in narrow buttons.

Checkpoint and validation

Validated head: 34fa4c1c4e7240c9c217d84baf8fb8666607868a, tree 7792c3217b7cbda6dedc0cc3849cacd71795211f, based on released main cf831490206cbe740fad94a07170ac3171ff68e7. Version 0.5.8 is the release candidate; publication follows merge and the independent tag workflow.

• Focused primitive suite: 7 passed, 0 failed, 1,903 assertions.
• Narrow primitive TypeScript and repository TypeScript checks passed.
• Independent static reviews of primitive implementation and packed/browser regressions passed.
• Canonical bun run check passed on the exact head through the host browser lane and repository exclusive scheduler. The scheduler released normally and no matching owned browser or build process survived.
• Inventory, repository types, build, committed-output parity, compiler/artifact checks and all nine absolute-root deterministic artifacts passed. The compiled stylesheet is unchanged.
• Packed React 18/19 consumers, package unions, Vite adopters and native custody, Next client/Node/edge and no-edge production adopters, packed Bun browser, and the native primitive gallery passed.
• Canonical unit suite: 635 passed, 0 failed, 31,746 assertions; native Vite custody: 5 passed. The new gallery proves native heading/ref, live status updates, accessible button labels and containment under hostile consumer CSS.
• Current-head GitHub CI 34290148712 and CodeQL 34290143911 passed. No review threads remain unresolved. Static implementation and packed/browser regression reviews found no outstanding blocking issue.

Takeover and delivery

Merge the verified current head and publish immutable v0.5.8 through the existing tag workflow. Keep the separate Next development-adapter work in PR #59, now candidate v0.5.9. Consumers upgrade after the release is verified. Organization-wide migration is not complete.