chore(plans): link gitsheets-2.11 to PR #258

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011Q2tgjZEUrtvVk6k8SpdXJ

Author: themightychris

plans/gitsheets-2.11.md

@@ -7,7 +7,7 @@ upstream-specs:
   - gitsheets:specs/api/repository.md
   - gitsheets:specs/api/transaction.md
   - gitsheets:specs/behaviors/push-sync.md
-pr:
+pr: 258
 ---
 
 # Plan: adopt gitsheets 2.11 and retire the reconcile side handle