Creates a manual double-entry accounting transaction.

Use this endpoint for explicit accounting adjustments, such as transferring an
amount from a landlord or agency account to a tenant account after the tenant paid
an invoice directly. Account and leasing-contract references must be public IDs
returned by the corresponding Rivage API endpoints.

Send these fields at the root of the JSON body. A body wrapped in an
accounting_transaction object is accepted as well.

Requirements:

• At least two accounting entries
• Total debits must equal total credits
• Every line must contain exactly one positive debit or credit amount, as an integer number of cents
• All referenced accounts and leasing contracts must belong to the authenticated customer
• leasing_contract_id, when provided, must belong to the scope of the line's accounting account
• operation_date is optional and defaults to effective_date

The transaction is created in the manual_entry journal. Rivage also creates the
corresponding accounting event and runs the same balance refresh and downstream
processing as a manual journal entry created in the application.