refactor(pchome): extract controlled apply executor

tests/test_pchome_mapping_backlog_modularization.py

@@ -1,7 +1,13 @@
 from pathlib import Path
 
 from services import pchome_mapping_backlog_service as compatibility_facade
-from services.pchome_mapping_backlog import contracts, evidence, policies
+from services.pchome_mapping_backlog import (
+    artifacts,
+    contracts,
+    controlled_apply_executor,
+    evidence,
+    policies,
+)
 
 
 ROOT = Path(__file__).resolve().parents[1]
@@ -39,7 +45,57 @@ def test_extracted_unit_parser_preserves_ai_exception_and_no_write_contract():
     assert parsed["fetches_external_sites"] is False
 
 
-def test_legacy_facade_is_smaller_after_first_p0_extraction():
+def test_controlled_apply_executor_helpers_keep_legacy_import_identity():
+    assert (
+        compatibility_facade._canonical_retry_exception_artifact_bytes
+        is artifacts._canonical_retry_exception_artifact_bytes
+    )
+    assert (
+        compatibility_facade._selector_to_pchome_match_params
+        is controlled_apply_executor._selector_to_pchome_match_params
+    )
+
+
+def test_controlled_apply_executor_core_is_no_write_without_apply_request(tmp_path):
+    preflight = {
+        "policy": "controlled_apply_preflight_fixture",
+        "success": True,
+        "generated_at": "2026-07-11T12:00:00+08:00",
+        "stats": {},
+        "backlog": {},
+        "summary": {"mutation_plan_count": 1},
+        "controlled_apply_preflight": {
+            "preflight_id": "preflight-1",
+            "run_id": "run-1",
+            "ready_for_controlled_apply_executor": True,
+        },
+        "target_selectors": [
+            {
+                "selector_id": "selector-1",
+                "momo_product_id": "MOMO-1",
+                "momo_product_name": "Example 40ml",
+                "target_pchome_product_id": "PCH-1",
+                "target_pchome_product_name": "Example 40ml",
+                "target_match_score": 0.91,
+            }
+        ],
+    }
+
+    result = controlled_apply_executor.build_controlled_apply_executor_from_preflight(
+        preflight,
+        artifact_root=tmp_path,
+    )
+
+    assert result["result"] == "DIRECT_MAPPING_RETRY_EXCEPTION_CONTROLLED_APPLY_EXECUTOR_READY"
+    assert result["summary"]["target_selector_count"] == 1
+    assert result["summary"]["applied_record_count"] == 0
+    assert result["summary"]["rollback_step_count"] == 1
+    assert result["safety"]["execute_apply"] is False
+    assert result["safety"]["writes_database_count"] == 0
+    assert result["safety"]["writes_artifact_count"] == 0
+
+
+def test_legacy_facade_is_smaller_after_second_p0_extraction():
     facade = ROOT / "services/pchome_mapping_backlog_service.py"
 
-    assert sum(1 for _ in facade.open(encoding="utf-8")) < 44_300
+    assert sum(1 for _ in facade.open(encoding="utf-8")) < 44_000