feat(feedback): render links in the operator reply (open in a new tab)

Linkify the operator reply on the feedback screen: http/https/ftp/mailto/tel URLs
become anchors (target=_blank rel=noopener), everything else stays escaped text.
A small whitelisted regex (no dependency) — the reply is operator-authored, so
explicit schemes suffice; dangerous schemes (javascript:/data:) are never linked,
and \b avoids matching a scheme inside a word (hotel:, email:).

docs/FUNCTIONAL.md

@@ -179,8 +179,8 @@ PDF, text/log, office documents, RTF or archives; an unsupported file is refused
 without naming the allowed types). After sending, the form clears and confirms "Ваше сообщение
 отправлено", and sending is blocked until the operator has dealt with that message — on re-entry
 the screen reads "Ожидаем рассмотрения вашего последнего обращения". The operator's reply appears
-below the form as "Ответ на ваше последнее сообщение"; it is marked read once the screen shows it
-and disappears a week later. A badge on the Settings tab (and on Info inside it) flags an
+below the form as "Ответ на ваше последнее сообщение" (any link in it opens in a new tab); it is
+marked read once the screen shows it and disappears a week later. A badge on the Settings tab (and on Info inside it) flags an
 unanswered reply. Guests cannot send feedback (the entry is hidden). A player the operator has
 barred from feedback (a role, not a full account block) sees the send control disabled.