Change Box-in-Text validation from dev-only warn+skip to unconditional
throw, matching Ink's reconciler behavior. Add text-outside-Text
validation that throws when non-empty text-leaf nodes are inserted into
box/root/static containers outside a Text context.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Detect invalid <Box> inside <Text> nesting at the DOM insert level and
emit a dev warning instead of crashing the WASM yoga engine. The box
insertion is skipped to prevent layout corruption.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>