refactored notificatoin / tgsettle responsibility boundaries

api/proto/common/payment/v1/ledger.proto

@@ -4,11 +4,14 @@ package common.payment.v1;
 
 option go_package = "github.com/tech/sendico/pkg/proto/common/payment/v1;paymentv1";
 
-
+// LedgerDetails identifies an internal ledger account as a payment endpoint.
 message LedgerDetails {
+  // id is the unique identifier for this endpoint instance.
   string id = 1;
   oneof source {
+    // ledger_account_ref is the direct ledger account reference.
     string ledger_account_ref = 2;
+    // account_code is a human-readable account code resolved at runtime.
     string account_code = 3;
   }
 }