fix: address account valuation review findings

tests/test_service.py

@@ -216,8 +216,8 @@ def test_statement_status_account_update_and_balance_reconciliation(tmp_path):
     report = service.get_balance_reconciliation_report(account_id=account_id, db_path=db_path)
     assert report["success"] is True
     assert report["items"][0]["calculated_balance"] == 901_500
-    assert report["items"][0]["difference"] == 0
-    assert report["items"][0]["status"] == "OK"
+    assert report["items"][0]["difference"] is None
+    assert report["items"][0]["status"] == "INCOMPLETE_CALCULATION"
 
     updated = service.update_ledger_account(account_id, statement_status="partial_import", last_balance=905_000, db_path=db_path)
     assert updated["success"] is True
@@ -226,9 +226,9 @@ def test_statement_status_account_update_and_balance_reconciliation(tmp_path):
     review = service.get_balance_reconciliation_report(account_id=account_id, baseline_balance=905_000, baseline_at="2026-06", db_path=db_path)
     assert review["success"] is True
     assert review["baseline_at"] == "2026-06-30T23:59:00+09:00"
-    assert review["items"][0]["difference"] == 3_500
-    assert review["items"][0]["status"] == "REVIEW_NEEDED"
-    assert "확인필요" in review["items"][0]["recommended_decisions"]
+    assert review["items"][0]["difference"] is None
+    assert review["items"][0]["status"] == "INCOMPLETE_CALCULATION"
+    assert review["items"][0]["recommended_decisions"] == []
 
 
 def test_balance_reconciliation_uses_account_last_synced_at_when_baseline_at_omitted(tmp_path):
@@ -251,8 +251,8 @@ def test_balance_reconciliation_uses_account_last_synced_at_when_baseline_at_omi
     assert report["baseline_at"] is None
     assert report["items"][0]["baseline_at"] == "2026-01-31T23:59:00+09:00"
     assert report["items"][0]["calculated_balance"] == 1_000
-    assert report["items"][0]["difference"] == 0
-    assert report["items"][0]["status"] == "OK"
+    assert report["items"][0]["difference"] is None
+    assert report["items"][0]["status"] == "INCOMPLETE_CALCULATION"
 
     explicit = service.get_balance_reconciliation_report(
         account_id=account_id,
@@ -264,8 +264,8 @@ def test_balance_reconciliation_uses_account_last_synced_at_when_baseline_at_omi
     assert explicit["baseline_at"] == "2026-02-28T23:59:00+09:00"
     assert explicit["items"][0]["baseline_at"] == "2026-02-28T23:59:00+09:00"
     assert explicit["items"][0]["calculated_balance"] == 800
-    assert explicit["items"][0]["difference"] == 0
-    assert explicit["items"][0]["status"] == "OK"
+    assert explicit["items"][0]["difference"] is None
+    assert explicit["items"][0]["status"] == "INCOMPLETE_CALCULATION"
 
 
 def test_invalid_statement_status_rejected(tmp_path):