diagram: Button silently drops data-testid and other unlisted props #959

The diagram's Button component only passes an explicit list of props to the <button> it renders and silently drops everything else.
ModuleDetails.tsx passes data-testid="add-input-button", which never reaches the DOM, so a test using getByTestId finds nothing.
TypeScript does not catch it because hyphenated JSX attributes (data-*, aria-*) skip excess-property checks.

Most of the other components in src/diagram/components/ use the same allowlist pattern; only a few (TextField, IconButton, Autocomplete, Snackbar, SvgIcon, icons) forward the rest.
Button is the only one with a known dropped attribute today.

Fix

Recommended: type Button's props as extending React.ButtonHTMLAttributes<HTMLButtonElement> and spread the remaining props onto the element, which also removes the three hand-listed aria-* props.
Do the same for other allowlist components when they next need it.
Alternative: delete the dead data-testid and leave the components explicit-only; smaller, but the trap stays.

Pointers

• src/diagram/components/Button.tsx
• src/diagram/ModuleDetails.tsx (add-input-button)