Bootstrap copied BFF and local accounts with public Sendico contracts (#34)

backend/contracts/sendico/api/ledger_accounts/response/balance.yaml

@@ -0,0 +1,15 @@
+components:
+  schemas:
+    LedgerAccountBalanceData:
+      description: Response payload containing a ledger account balance.
+      type: object
+      additionalProperties: false
+      required:
+        - accessToken
+        - balance
+      properties:
+        accessToken:
+          description: Refreshed access token to be used in subsequent API calls.
+          $ref: ../../../models/auth/token_data.yaml#/components/schemas/TokenData
+        balance:
+          $ref: ../../../models/ledger/balance.yaml#/components/schemas/LedgerAccountBalance