ver. 0.296: REST API for ordersPRO — orders management, dictionaries, API key auth

- New API layer: ApiRouter, OrdersApiController, DictionariesApiController
- Orders API: list (with filters/pagination/updated_since), details, change status, set paid/unpaid
- Dictionaries API: order statuses, transport methods, payment methods
- X-Api-Key authentication via pp_settings.api_key
- OrderRepository: listForApi(), findForApi(), touchUpdatedAt()
- updated_at column on pp_shop_orders for polling support
- api.php: skip session for API requests, route to ApiRouter
- SettingsController: api_key field in system tab
- 30 new tests (666 total, 1930 assertions)

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docs/PROJECT_STRUCTURE.md

@@ -72,6 +72,20 @@ Newsletter, Search, ShopBasket, ShopClient, ShopCoupon, ShopOrder, ShopProducer,
 ### Widoki (`front\Views\`) — 11 klas statycznych
 Articles, Banners, Languages, Menu, Newsletter, Scontainers, ShopCategory, ShopClient, ShopPaymentMethod, ShopProduct, ShopSearch
 
+## Warstwa API (`autoload/api/`)
+
+REST API dla ordersPRO. Entry point: `api.php`. Stateless (bez sesji), autentykacja przez `X-Api-Key` header.
+
+### Router: `api\ApiRouter`
+- `handle()` — autentykacja → routing → dispatch
+- Helpery statyczne: `sendSuccess()`, `sendError()`, `getJsonBody()`, `requireMethod()`
+
+### Kontrolery (`api\Controllers\`)
+- `OrdersApiController` — lista, szczegoly, zmiana statusu, platnosc (5 akcji)
+- `DictionariesApiController` — statusy, transporty, metody platnosci (3 akcje)
+
+Dokumentacja: `docs/API.md`
+
 ## Warstwa wspoldzielona (`autoload/Shared/`)
 
 | Klasa | Opis |
@@ -106,7 +120,7 @@ ProductRepository::productSetsWhenAddToBasket:{id}       — zestawy "kupowane r
 |------|------|
 | `index.php` | Frontend — autoload, sesja, DB, routing (`front\App`), layout (`front\LayoutEngine`), DOM post-processing |
 | `ajax.php` | Frontend AJAX — koszyk, transport, kontakt |
-| `api.php` | REST API (Ekomi CSV) |
+| `api.php` | REST API (ordersPRO + Ekomi CSV) — router: `\api\ApiRouter`, kontrolery: `\api\Controllers\` |
 | `admin/index.php` | Admin — autoload, sesja, DB, routing (`admin\App`) |
 | `admin/ajax.php` | Admin AJAX |
 | `cron.php` | CRON: Apilo sync (ceny/stany co 10min, cennik co 1h, retry queue) |