This section follows runtime semantics: how an AUP tree expresses intent, how events and data change it, how a session delivers change to a renderer, and how missing device capability produces an explicit degradation or refusal.
Read in this order
- Semantic tree for the node/data/child model.
- Events, state, and bindings for declared interaction and data directions.
- Sessions, patches, and scenes for the interactive delivery path.
- Device capabilities and degradation for target-specific support rather than assumed portability.
- Caller identity and safety before treating a UI condition as authorization.