Accrual Entry with Automated Reversal

negative) when the reversal_date falls in a CLOSED period then POST of the accrual returns 422 "reversal.date_in_closed_period".

At period end, an accountant creates an accrual journal entry to recognize an expense or revenue that has been incurred but not yet invoiced (e.g., unbilled vendor services). The entry debits the expense account and credits an accrued liabilities account. When creating the entry, the accountant toggles the "Auto-reverse" flag and specifies the reversal date (typically the first of the next month). The system posts the accrual in the current period and simultaneously schedules the reversal. On the reversal date, the system auto-posts the reversing entry and sends a notification. The accountant can verify the reversal in the transaction listing and confirm the accrued liability balance returns to zero.

Given an accountant creates a journal entry with auto_reverse=true and a reversal_date;
when the system reaches the reversal_date;
then the reversal entry is auto-posted, a notification is sent, and the original accrual's reversed_by_id is populated;
(negative) when the reversal_date falls in a CLOSED period then POST of the accrual returns 422 "reversal.date_in_closed_period".

journal_entries { id: string, external_id: string, auto_reverse: bool, reversal_date: date, reversal_entry_id: string, entry_type: enum(ACCRUAL,...) };
(reference, product may differ).

POST /v1/journal-entries { auto_reverse: true, reversal_date, ...lines } -> 201 { id, reversal_date, status: PENDING_APPROVAL };
system auto-posts reversal on reversal_date;
emits gl.accrual_reversal.posted event;
GET /v1/journal-entries/{id} returns { auto_reverse, reversal_date, reversal_entry_id };
idempotent via external_id.

Accrual entry: DRAFT -> PENDING_APPROVAL -> POSTED;
on reversal_date system transitions to REVERSED;
auto-reversal entry born POSTED;
guard: original accrual cannot be deleted after reversal_entry_id is set.