feat: require pagination proof in reconciliation PR inventory (#308)

Add assess_reconcile_inventory_report verifier to block complete queue scan
and all-already-landed claims without final-page metadata, requested page size,
pages fetched, per-page counts, and no-next-page proof. Wire into
build_final_report and export from review_proofs.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

review_proofs.py

@@ -1476,6 +1476,11 @@ def build_final_report(checkout_proof, inventory, validation, contamination,
         if report_text
         else {"proven": True, "block": False, "reasons": [], "violations": []}
     )
+    reconcile_inventory = (
+        assess_reconcile_inventory_report(report_text)
+        if report_text and _RECONCILE_INVENTORY_HINT.search(report_text)
+        else {"proven": True, "block": False, "reasons": []}
+    )
     if baseline_validation is None and report_text:
         baseline_validation = assess_reviewer_baseline_validation_proof(
             report_text=report_text,
@@ -1632,6 +1637,11 @@ def build_final_report(checkout_proof, inventory, validation, contamination,
             "queue-status report violates loaded workflow proof gates (#339)"
         )
         downgrade_reasons.extend(queue_status_report.get("reasons", []))
+    if not reconcile_inventory.get("proven"):
+        downgrade_reasons.append(
+            "reconciliation PR inventory lacks pagination proof (#308)"
+        )
+        downgrade_reasons.extend(reconcile_inventory.get("reasons", []))
     if not baseline_validation.get("proven"):
         downgrade_reasons.append(
             "reviewer baseline validation proof missing or failed (#325)"
@@ -1717,6 +1727,10 @@ def build_final_report(checkout_proof, inventory, validation, contamination,
         "queue_status_violations": list(
             queue_status_report.get("violations") or []
         ),
+        "reconcile_inventory_proven": bool(reconcile_inventory.get("proven")),
+        "reconcile_inventory_violations": list(
+            reconcile_inventory.get("reasons") or []
+        ),
         "baseline_validation_proven": bool(baseline_validation.get("proven")),
         "baseline_validation_violations": list(
             baseline_validation.get("violations") or []
@@ -3753,6 +3767,12 @@ _QUEUE_STATUS_REPORT_HINT = re.compile(
     re.I,
 )
 
+_RECONCILE_INVENTORY_HINT = re.compile(
+    r"already[- ]landed reconciliation|reconcile[- ]landed|"
+    r"open pr inventory|inventory pagination proof",
+    re.I,
+)
+
 _GATE_PASSED_VALUE = re.compile(r"\bpassed\b", re.I)
 
 _NOT_APPLICABLE_VALUE = re.compile(
@@ -4142,3 +4162,10 @@ def assess_non_mergeable_skip_proof(report_text, **kwargs):
     from reviewer_mergeability_skip import assess_non_mergeable_skip_proof as _assess
 
     return _assess(report_text, **kwargs)
+
+
+def assess_reconcile_inventory_report(report_text, **kwargs):
+    """#308: prove PR inventory pagination in reconciliation reports."""
+    from reviewer_reconcile_inventory import assess_reconcile_inventory_report as _assess
+
+    return _assess(report_text, **kwargs)