docs(plans): record scheduled-spam-purge PR

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TGqwPjt3v4eMfiHpPmCKnR

Author: themightychris

plans/scheduled-spam-purge.md

@@ -6,6 +6,7 @@ specs:
   - specs/api/moderation.md
   - specs/screens/admin-members.md
 issues: []
+pr: 253
 ---
 
 # Plan: Purge spam-voted accounts automatically after three days