Breakdowns, series and schedules

What else changed

• Tax breakdowns travel complete. Every breakdown line is present in the response, and their bases add up to the invoice base exactly — the rounding remainder is distributed rather than left to fall where it may, so base × rate no longer disagrees with the amount charged. Lines that carry no tax no longer report a phantom main_tax.
• next_number is the number that will actually be assigned. It is resolved with the same rule the issuing path uses, so it accounts for the series' counter reset policy: a series that resets annually publishes the first number of the current year, not the last one of the previous year.
• numbering_locked tells you whether you can still change how a series numbers. It is true once the series has issued its first invoice; from that point code, format, counter_reset and initial_number are permanently locked. A draft does not lock anything — it has consumed no number yet.
• Corrective invoices. A partial corrective inherits the defaults of the invoice it corrects instead of requiring them again, and a corrective invoice cannot itself be corrected.
• Recurring invoices declare frequency in the request contract, and an unsupported value is rejected with 422 naming it, instead of being accepted and quietly producing nothing.
• VeriFactu submission status gains NOT_SUBMITTED for an invoice that was never sent. Reading it no longer requires inferring absence, and filtering by submission status now matches the value the invoice itself reports.
• Voiding. voided_at is the instant the system recorded the void, not a date the client supplies.