Create AuditPageHelper with requirePurgePost() and findOrRedirect() to eliminate duplicated POST/CSRF guard boilerplate across 4 purge pages and find-or-redirect boilerplate across 4 view pages. Each page retains its stream-specific logic (system-audit event recording, user-lifecycle snapshot/restore). Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>