An ongoing migration is moving all business logic into `rust/`. Each app under `apps/` is a UI shell — it owns rendering, interaction, and platform-specific concerns, but never owns logic. The UI framework for any given app is a replaceable detail.
The single source of truth for all non-UI code. Everything platform-agnostic belongs here: no components, no hooks, no framework imports.
### `apps/`
Each app is a frontend that calls into Rust. Logic is never duplicated between apps — only UI is, because each platform may use an entirely different framework and language to build it.