React UI authoring

vgai presents each declared React adapter root as a native hierarchy. Its JSX is the authored document: supported inspector edits write directly to .tsx, and the same root mounts in Edit/Play and standalone builds.

In this section

• UI in the game hierarchy — find React roots and their OID-backed JSX elements.
• React UI roots — manifest declaration, game-state subscriptions, input, and lifecycle.
• React adapter roots — JSX truth, composition, and the unmanaged-root guard.
• Build a React root — an editor-first worked lesson.

One authoring model

There is no scene-authored UI document or separate UI editor page in v2. React UI is a declared adapter root, beside Three.js and PixiJS roots.