feat: split nights off an accommodation booking as separate periods

addresses #869f6z36v

docs/api-consumer-guide.md

@@ -555,14 +555,16 @@ Single booking by UUID. `404 {"message":"Not found"}` if unknown.
   "totalDiscountLabel": null,
   "totalPrice": 123456,
   "pricingCurrency": "EUR",
-  "pricingVersion": 3,
+  "pricingVersion": 2,
   "priceBreakdown": {}
 }
 ```
 
 `totalPrice` and `totalDiscountAmount` are integer **minor units** (cents) — unlike the contingent endpoints. The three `*Discount` fields are whole **percentages** (1–100) or `null`, not amounts. `dateFrom`/`dateTo` are `Y-m-d`; `acceptedAt` is a full ISO-8601 datetime and is `null` until accepted. `priceBreakdown` is a computed nested structure.
 
-The first three discounts each apply to one section of the breakdown: `accommodationDiscount` to `basePrice + additionalPersonsPrice`, `boardServiceDiscount` to `boardPrice`, `additionalServicesDiscount` to `servicesPrice`. Surcharges and running costs sit in `total` but in no section, so they are never discounted.
+The first three discounts each apply to one section of the breakdown: `accommodationDiscount` to `basePrice + additionalPersonsPrice`, `boardServiceDiscount` to `boardPrice`, `additionalServicesDiscount` to `servicesPrice`. Surcharges, running costs and the lines of split-off periods sit in `total` but in no section, so the section discounts never reach them; only `totalDiscountAmount` does.
+
+`dateFrom`/`dateTo`/`nights` span the whole stay. The office can split nights off its start or end, for example for an advance team arriving before the group. Such a split-off period has no headcount, board or services of its own; it is priced as free-form lines instead. `paxCount`, `minorsCount`, `childrenCount`, `boardService` and `additionalServices` describe the **group**, which stays for what remains between the split-off periods. The split-off periods are listed in `priceBreakdown.periods`, below. A booking nobody split has an empty list there, and its group stays for the whole stay.
 
 `totalDiscountAmount` is a freely named discount on the whole price, labelled by `totalDiscountLabel`. It is a fixed sum, not a percentage, and is subtracted **after** the three section discounts have reduced `total`. It is capped at what is left of that subtotal, so `discountedTotal` is never negative and the amount shown in the breakdown may be smaller than `totalDiscountAmount` itself. The section discounts are each rounded to the nearest cent as they are applied.
 
@@ -570,6 +572,10 @@ The first three discounts each apply to one section of the breakdown: `accommoda
 
 | field | meaning |
 | --- | --- |
+| `nights` | the group's nights, which are fewer than the booking's `nights` when periods were split off |
+| `periods` | list of `{position, label, dateFrom, dateTo, nights, lines, total}`, at most one per side, in date order; `position` is `leading` (before the group) or `trailing` (after it), `label` is the office's name for the period or `null`, `lines` is a list of `{label, amount}`, and `total` is their sum |
+| `periodsTotal` | the sum of all `periods[].total` |
+| `total` | the price before discounts, the group's rows plus `periodsTotal` |
 | `discounts` | list of `{label, percent, amount}` for the section discounts; entries rounding to `0` are omitted, and `label` already includes its `Rabatt ` prefix |
 | `discountSubtotal` | `total` minus the section discounts — present only when `totalDiscountAmount` applies *and* at least one section discount did, otherwise `null` |
 | `totalDiscountDetails` | `{label, amount}` for the total discount, or `null`; `amount` is the capped figure actually subtracted |