View / React Rules

React is display-only UI and user-intent capture.
React must not own, manage, derive authoritative, or mutate document/editor state.
React may keep only local UI state with no app meaning, e.g. popover open state or unsent input draft.
Event handlers, toolbar buttons, menus, and effects must request state changes by dispatching commands.
Do not implement business rules, document mutation, renderer backend logic, or editor workflow ownership in components.
Effects are for subscriptions and UI integration only.
Keep canvas components small. Extract renderer lifecycle, resize observation, input wiring, cursor logic, and other DOM integration into focused hooks/files under view/canvas/.