Refactor import and workflow services plus adapter seams

jarca_ledger_mcp/adapters/streamlit/transfers_gateway.py

@@ -0,0 +1,11 @@
+from __future__ import annotations
+
+from ...service import (
+    find_cancel_original_candidates,
+    find_self_transfer_candidates,
+    link_cancel_to_original,
+    link_self_transfer_pair,
+    list_cross_transfer_review_queue,
+    preview_cross_account_transfers,
+    run_cross_account_transfer_match,
+)