feat(enakgame): spin as an EnakGame game; remove the old game flow

EnakGame phase 10 of docs/tasks-enakgame.md (EG-1001 to EG-1003).

Spin (EG-1001)
- PROBABILITY entries take an optional label (a wheel segment). The customer game
  list shows a PROBABILITY game's prizes (entry, label, amount, never weights), and
  completing returns the drawn prize, so the client can draw the wheel and stop it
  on the server's draw.
- docs/enakgame-spin.md: the admin steps to set up spin per organization (no
  seeder) and the customer app flow. An HTTP test plays it end to end.

Old game flow removed (EG-1002)
- Routes POST /customer/spin, GET /customer/games, GET /customer/ferris-wheel, and
  admin /marketing/games, /marketing/game-prizes, /marketing/rewards, with their
  handlers, services, processors, repositories, validators, models, contracts,
  mappers and tests (GamePlayProcessor, SpinGameService, rewards, ...). This also
  closes RFC §15 findings 1 and 2 (double charge, spinning another org's game).
- Tables games, game_prizes, game_plays and rewards stay for ledger history.
  entities.StringSlice moves to its own file; the omset tracker (unrouted) keeps
  game_id but no longer embeds the old game response.

games.is_active dropped (EG-1003)
- Migration 000115; nothing reads metadata.coin_cost any more.

The EnakPoint integration docs now point at /customer/enakgame. The Postgres tests
were not run: no test database here. Migration 000115 has not been run anywhere.
The customer app must stop calling the removed endpoints before this is deployed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docs/api-enakpoint.md

@@ -151,7 +151,7 @@ PIN baru ditolak `304` bila bukan 6 digit, konfirmasinya beda, semua digit sama
 | POST | `/customer/wallet/exchange` | Ya | Wajib |
 | GET | `/customer/wallet/transfer/recipient?phone=` | – | – |
 | POST | `/customer/wallet/transfer` | Ya | Wajib |
-| POST | `/customer/spin` | – | – |
+| POST | `/customer/enakgame/sessions` | – | Wajib |
 
 ### GET /customer/wallet/exchange/preview?coins=30
 
@@ -210,19 +210,15 @@ Body `{ "currency": "POINT", "amount": 120, "recipient_phone": "081234561234", "
 
 `currency` = `POINT` atau `COIN`. Batas organisasi (transfer aktif, minimal, maksimal per transaksi, batas harian per currency yang reset tengah malam WIB) ditolak `304` sebelum PIN dicek. Transfer final. Saldo membawa tanggal kedaluwarsa aslinya ke penerima (`lots`), dan penerima mendapat push `WALLET_TRANSFER_IN`.
 
-### POST /customer/spin
+### Game (EnakGame)
 
-Body `{ "spin_id": "<id game>" }`. Memotong EnakCoin sebesar `metadata.coin_cost` game itu (default 1).
+`POST /customer/spin`, `GET /customer/games`, dan `GET /customer/ferris-wheel` sudah dihapus. Semua game, termasuk spin, dimainkan lewat `/customer/enakgame`:
 
-```json
-{
-  "game_play": { "id": "…", "game_id": "…", "coins_used": 1, "created_at": "…" },
-  "prize_won": { "id": "…", "name": "Voucher 10rb" },
-  "coins_remaining": 7
-}
-```
+- `GET /customer/enakgame/games`: game aktif dengan `entry_cost` (EnakCoin per main) dan, untuk spin, `prizes` (segmen roda).
+- `POST /customer/enakgame/sessions` dengan `{ "game_id": "…" }` dan `Idempotency-Key`: memotong `entry_cost`.
+- `POST /customer/enakgame/sessions/:id/complete`: server menghitung hadiah EnakCoin; untuk spin, response berisi `prize` (segmen yang keluar).
 
-EnakCoin kurang, game nonaktif, atau hadiah baru saja habis → `304`, tidak ada EnakCoin yang terpotong.
+Alur spin lengkap ada di [`enakgame-spin.md`](./enakgame-spin.md).
 
 ## POS: earning, void, dan refund