feat: add idempotency support for settlement adjustments and payments, fix rebate handling

- Added idempotency_key parameter to settlement bill adjustment and payment endpoints to prevent duplicate operations
- Fixed player rebate profile updates to preserve existing values when only one field is modified
- Moved wallet player validation earlier in AdminPlayerStoreController to prevent unnecessary processing
- Enhanced extra rebate calculation to include 'in_bill' and 'settled' statuses in AgentP

app/Http/Controllers/Api/V1/Admin/AgentSettlement/AgentSettlementBillPaymentController.php

@@ -35,6 +35,7 @@ final class AgentSettlementBillPaymentController extends Controller
                 'method' => $validated['method'] ?? null,
                 'proof' => $validated['proof'] ?? null,
                 'remark' => $validated['remark'] ?? null,
+                'idempotency_key' => $validated['idempotency_key'] ?? null,
             ],
         );