Explain protected PChome match conflicts

tests/test_competitor_intel_cache.py

@@ -220,6 +220,42 @@ def test_rescore_accepted_review_item_has_actionable_decision_envelope():
     assert any(evidence["metric"] == "candidate_gap_pct" for evidence in envelope["evidence"])
 
 
+def test_protected_existing_match_envelope_explains_candidate_conflict():
+    from services.competitor_intel_repository import _format_competitor_review_item
+
+    item = _format_competitor_review_item({
+        "sku": "14338675",
+        "name": "【Relove】胺基酸私密潔淨精華凝露120ml",
+        "momo_price": 399,
+        "attempt_status": "protected_existing_match",
+        "candidate_count": 2,
+        "best_competitor_product_id": "QEAE1O-A900A6DRS",
+        "best_competitor_product_name": "RELOVE胺基酸私密清潔凝露120ml",
+        "best_competitor_price": 329,
+        "best_match_score": 0.817,
+        "match_diagnostic_json": {
+            "match_type": "exact",
+            "price_basis": "total_price",
+            "alert_tier": "identity_review",
+            "reasons": ["strong_exact_spec_match", "spec_name_alignment"],
+        },
+        "error_message": (
+            "existing_match_conflict;existing_id=QEAE1O-A900A6DNN;"
+            "incoming_id=QEAE1O-A900A6DRS;existing_score=0.766;incoming_score=0.817"
+        ),
+    })
+
+    envelope = item["decision_envelope"]
+    conflict = envelope["expected_impact"]["existing_match_conflict"]
+    assert item["existing_match_conflict"]["score_delta"] == 0.051
+    assert envelope["recommended_action"]["action"] == "compare_existing_identity"
+    assert envelope["severity"] == "P2"
+    assert envelope["guardrails"]["existing_match_protected"] is True
+    assert conflict["existing_product_id"] == "QEAE1O-A900A6DNN"
+    assert conflict["incoming_product_id"] == "QEAE1O-A900A6DRS"
+    assert any(evidence["metric"] == "existing_match_conflict" for evidence in envelope["evidence"])
+
+
 def test_review_decision_brief_is_shared_by_openclaw_and_ppt():
     from services.competitor_intel_repository import (
         _format_competitor_review_item,