In-place editor for a pin’s type label — the smaller second line below the
name. The sibling of RenamePin (which edits the
name and the tag); entered by double-clicking the type line, and it returns to
the pin’s selection on commit. Always an active editor — never a resting tool.
The editor’s rect over the type line’s on-canvas rect, widened for
comfortable typing — re-measured every frame so it tracks the pin’s
geometry; None once the pin is gone.