Excalidraw

Builds shape attributes from the active tool and inserts a newly constructed element.

Initializes a typed Excalidraw element with stable identity and default shape fields.

Maintains ordered scene elements and triggers subscribers when scene state changes.

Derives the visible element set for the current viewport and editor state.

Owns the static HTML canvas and invokes the scene renderer after React updates.

Bootstraps the canvas and dispatches visible scene elements for painting.