Run citation verification as final step before sending PDF

Citation NEEDS-CHECK tags were being deleted by writer agent in
subsequent iterations. Now citation verification runs twice:
1. After compile (Step 1) — for CORRECTED fixes before review
2. Before send PDF (pre-delivery) — re-applies NEEDS-CHECK tags
   that writer may have removed. No writer runs after this point.

Applied to both Dev phase delivery and Review loop delivery.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: JihaoXin

ark/pipeline.py

@@ -452,6 +452,9 @@ def run_paper_iteration(self) -> bool:
         # Hard page count enforcement before delivery
         self._enforce_page_count(context="pre-delivery")
 
+        # Final citation verification — re-apply NEEDS-CHECK tags that writer may have removed
+        self._run_citation_verification()
+
         # Send iteration summary + PDF to Telegram
         self.send_iteration_summary(score, current_score, review_output)
 
@@ -1224,6 +1227,7 @@ def _run_dev_phase(self):
 
         if draft_compiled:
             self._enforce_page_count(context="dev-phase-delivery")
+            self._run_citation_verification()
 
         if draft_compiled and self.telegram.is_configured:
             pdf_path = self.latex_dir / "main.pdf"