Fix currency presentation and update resilience

tests/test_models.py

@@ -1,5 +1,15 @@
 """Tests for event payloads: no Home Assistant runtime is required."""
-from custom_components.up_banking.models import account_label, transaction_event
+from importlib.util import module_from_spec, spec_from_file_location
+from pathlib import Path
+
+
+_MODELS_PATH = Path(__file__).parents[1] / "custom_components" / "up_banking" / "models.py"
+_spec = spec_from_file_location("up_banking_models", _MODELS_PATH)
+assert _spec and _spec.loader
+_models = module_from_spec(_spec)
+_spec.loader.exec_module(_models)
+account_label = _models.account_label
+transaction_event = _models.transaction_event
 
 
 def test_account_label_includes_saver_and_ownership():
@@ -13,4 +23,4 @@ def test_transaction_event_is_small_and_automation_ready():
         "attributes": {"status": "HELD", "amount": {"value": "-12.34", "currencyCode": "AUD"}, "description": "Coffee", "createdAt": "2026-01-01T00:00:00Z", "rawText": "Cafe"},
         "relationships": {"account": {"data": {"id": "account-1"}}},
     }
-    assert transaction_event(transaction, "created") == {"transaction_id": "tx-1", "event_type": "created", "status": "held", "account_id": "account-1", "amount": "-12.34", "currency": "AUD", "description": "Coffee", "created_at": "2026-01-01T00:00:00Z", "raw_text": "Cafe"}
+    assert transaction_event(transaction, "created") == {"transaction_id": "tx-1", "event_type": "created", "status": "held", "account_id": "account-1", "amount": "-12.34", "currency": "$", "description": "Coffee", "created_at": "2026-01-01T00:00:00Z", "raw_text": "Cafe"}