Keep the comment marker's touch area inside the document

A slim chip in the phone padding had a 44px button that ran past the
document edge, where taps were clipped. The touch area is now clamped
inside the document around the chip, and the chip is positioned within
it. Tests find the grouped marker by its data while a modal sheet hides
the document, and check that the visible chip, not the touch area,
stays clear of prose.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>