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/backoffice-enakpoint.md

@@ -18,7 +18,7 @@ Semua endpoint di bawah base URL `/api/v1`, butuh login user dengan role Admin a
 | Wallet customer | `GET /marketing/customers/:id/wallet`, `POST …/wallet/adjust` | Customer → detail customer → tab Wallet |
 | Telusuri mutasi | `GET /marketing/wallet-transactions/:id/trace` | Dibuka dari baris riwayat wallet |
 | PIN & keamanan customer | `DELETE /marketing/customers/:id/pin`, `GET …/security-events` | Customer → detail customer → tab Keamanan |
-| Biaya main game | `PUT` game yang sudah ada, `metadata.coin_cost` | Marketing → Game → edit game |
+| Biaya main game | `entry_cost` di `/marketing/enakgame/games` | Marketing → EnakGame → game |
 
 Penempatan menu di atas adalah usulan; sesuaikan dengan struktur backoffice yang ada.
 
@@ -269,7 +269,7 @@ Admin tidak bisa membuat, mengganti, atau melihat PIN customer; satu-satunya aks
 
 ### Biaya main game
 
-Semua game (spin, raffle, minigame) memakai EnakCoin yang sama. Biaya per main diisi di `metadata.coin_cost` saat membuat atau mengedit game (`/marketing/games`): bilangan bulat ≥ 1, default 1 bila kosong. Nilai pecahan, 0, atau teks membuat game tidak bisa dimainkan. Karena `metadata` dikirim utuh, pertahankan key metadata lain saat menyimpan. Hadiah game juga bernilai rupiah secara tidak langsung, karena EnakCoin bisa ditukar ke EnakPoint.
+Semua game (spin, raffle, minigame) memakai EnakCoin yang sama dan dikelola di `/marketing/enakgame/games`. Menu lama `/marketing/games`, `/marketing/game-prizes`, dan `/marketing/rewards` sudah dihapus. Biaya per main adalah `entry_cost` game (bilangan bulat ≥ 1), hadiahnya diatur di reward config game itu. Langkah membuat spin ada di [`enakgame-spin.md`](./enakgame-spin.md). Hadiah game juga bernilai rupiah secara tidak langsung, karena EnakCoin bisa ditukar ke EnakPoint.
 
 ## Pesan error dan checklist
 
@@ -293,7 +293,7 @@ Pesan `cause` saat ini berbahasa Inggris, mis. `invalid loyalty settings: loyalt
 - [ ] Adjustment mewajibkan alasan dan mengirim `idempotency_key`.
 - [ ] Tombol Telusuri ada di setiap baris riwayat.
 - [ ] Hapus PIN mewajibkan alasan; tab Keamanan menampilkan log.
-- [ ] Form game punya input `coin_cost`.
+- [ ] Form game EnakGame punya input `entry_cost`.
 - [ ] Semua nilai rupiah EnakPoint ditulis "setara potongan Rp …".
 
 Transfer belum boleh dirilis sebelum tinjauan legal (N3) selesai. Layar backoffice boleh disiapkan lebih dulu.