# Domain 12 — Audit, Config & Reference

[← Database Model](index.md)

### `audit_logs` [CORE]
**Role:** Immutable, append-only record of every state change on sensitive entities — now explicitly **including `platform_configs`** (so finance can prove the commission rate at any moment). **Why:** compliance and accountability; `changed_fields_json` enables fast filtering. Plan month-partitioning + 2–3yr cold-storage archival before launch. Fields unchanged. **Relations:** polymorphic, append-only.

### `system_events` [MVP]
**Role:** High-volume behavioral/analytics event log. **Why kept but de-emphasized:** product analytics, not compliance. It grows unbounded — at scale, pipe it to an analytics sink/warehouse rather than the transactional DB. Fields unchanged.

### `platform_configs` [CORE]
**Role:** Key-value runtime business parameters — change without a deploy. **Why typed values:** `data_type` tells the app how to parse. **New keys** this revision: `dispute_window_hours` (default 72), `vat_rate` (0.10), `bnpl_merchant_of_record`, `bnpl_provider_commission_rate`, `bnpl_settlement_timing`, cancellation-tier defaults — alongside the existing `platform_fee_rate`, `booking_payment_deadline_minutes`, `nurse_response_deadline_hours`, `nurse_payout_interval_days`, `evv_location_tolerance_meters`, `min_rating_for_support_alert`. **Relations:** referenced everywhere; changes audited.

### `iranian_holidays` [MVP] — **NEW**
**Role:** Shared official/religious holiday calendar (movable, partly lunar-Hijri), with a `is_bank_closed` flag. **Why a real table:** Iran's holidays are numerous and partly movable, and they drive **payout bank-closure scheduling** (PAYA/SATNA closed → a weekly payout shifts to the next business day), optional holiday pricing, and business-hour deadline math — none of which a purely manual per-nurse availability exception can express.

| Field | Type | Notes |
|---|---|---|
| `id` | BIGINT PK | |
| `holiday_date` | DATE | |
| `name_fa` | NVARCHAR(200) | |
| `type` | NVARCHAR(20) | `official` / `religious` / `national` |
| `is_bank_closed` | BIT | Drives payout date shifting |

**Relations:** referenced by payout scheduling and (optionally) pricing.