Andreas signed up as "andreas" and was shown that way everywhere. A name
is now capitalised on the way in — the first letter of each word raised,
the rest left as typed — in CreateUser (signup and invite-accept) and
UpdateProfile, so display, mail and export all agree.
Existing accounts are fixed by an idempotent startup pass
(NormalizeUserNames), the same shape as SealNotes: the rule is Unicode-aware
and per word, which SQLite's UPPER cannot spell, so it lives in Go rather
than a migration.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>