Optimize PChome review queue paging

tests/test_competitor_match_attempts_persistence.py

@@ -39,6 +39,22 @@ def test_competitor_dashboard_hot_paths_use_latest_price_lateral_lookup():
         assert "lm.rn = 1" not in body
 
 
+def test_competitor_review_queue_page_uses_single_paged_total_query():
+    source = (ROOT / "services/competitor_intel_repository.py").read_text(encoding="utf-8")
+    page_body = _function_body(
+        source,
+        "_fetch_competitor_review_queue_page_uncached",
+        "_fetch_competitor_review_queue_uncached",
+    )
+
+    assert "total_rows AS" in page_body
+    assert "paged_rows AS" in page_body
+    assert "LEFT JOIN paged_rows ON TRUE" in page_body
+    assert "SELECT COUNT(*) AS total FROM review_rows" not in page_body
+    assert "rows[0].get(\"total_count\")" in page_body
+    assert "if row.get(\"sku\")" in page_body
+
+
 def test_competitor_feeder_persists_all_match_attempt_outcomes():
     source = (ROOT / "services/competitor_price_feeder.py").read_text(encoding="utf-8")
     migration = (ROOT / "migrations/023_competitor_match_attempts.sql").read_text(encoding="utf-8")