Excalidraw diagram creator

Produce a native .excalidraw file that explains a relationship, plus an inspection of the native canvas. The workflow is the same in Claude Code and Codex.

Quality contract

A diagram moves through four distinct states:

Structurally valid. JSON, numbers, IDs, files, and reciprocal bindings pass the validator.
Layout previewed. The lightweight renderer exposes obvious geometry defects but does not prove native rendering.
Visually approved. Inspect pixels from an official Excalidraw surface and correct clipping, overlap, weak hierarchy, ambiguous flow, and edge crowding.
Handed off. The editable artifact and its verification state are clear to the user.