post https://example.com/api/instrument//cashflows
Get cashflows for a debt instrument.
Returns calculated cashflows with database overrides applied. If as_of_date is provided, returns only future cashflows (transaction_date >= as_of_date). If as_of_date is None, returns all cashflows since inception.
Args: instrument_id: ID of the instrument request: Cashflow request with quantum and optional as_of_date session: Database session
Returns: List of cashflow items
Raises: HTTPException: 404 if instrument not found, 400 for validation errors