feat(fusion_accounting_ai): wire BankRecAdapter fusion paths to engine

Enhances list_unreconciled_via_fusion to include fusion fields
(top_suggestion_id, confidence_band, attachment_count). Adds 3 new
adapter methods that proxy the engine: suggest_matches, accept_suggestion,
unreconcile. AI tools (Task 22+) and OWL controller (Task 26) will call
these adapter methods instead of touching the engine directly.

Made-with: Cursor

fusion_accounting_bank_rec/tests/__init__.py

@@ -10,3 +10,4 @@ from . import test_reconcile_engine_property
 from . import test_factories
 from . import test_reconcile_engine_integration
 from . import test_bank_rec_prompt
+from . import test_bank_rec_adapter