Update Risk Status

Update a risk's status and resolved flag. If setting status to "flag" for a non-marketing run and there's no linked Issue yet, create an Issue and link it to the DocumentRisk.

For marketing dismissed, require dismiss_reason; other also requires a non-empty dismiss_note. TipTap notes is the source of truth for reviewer text: we add a single managed Dismissed for: {reason} seed line only while Notes are empty or still lead with that seed. A fresh dismissal's free-text note is appended as a trailing reviewer-owned paragraph; editing an existing dismissal replaces that note paragraph in place (or removes it when cleared) — the client prefills the modal from dismiss_note, so an edit never duplicates or strands a stale note. Clearing dismiss strips the leading seed line and the modal-note paragraph it appended (tracked 1:1 by dismiss_note), keeping Notes consistent with the now-null dismiss_note; genuinely hand-authored paragraphs are preserved.