fix(web): project monograms over two characters can no longer be saved

The icon picker only checked the contract pattern, which still admits longer
legacy monograms, so ABC looked valid and the server rejected it after the
dialog closed. Count graphemes the way the server does so the field shows as
invalid and Save stays disabled.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
def9e75af2Julius Marminge committed on 10/21/2026, 10:48:57 PMparent70e5e38
1 file changedLine totals unavailable