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/AgentSettlementBillAdjustmentController.php

@@ -33,6 +33,7 @@ final class AgentSettlementBillAdjustmentController extends Controller
             (string) ($request->validated('adjustment_type') ?? 'adjustment'),
             $request->validated('reason'),
             (int) $admin->id,
+            $request->validated('idempotency_key'),
         );
 
         $after = DB::table('settlement_bills')->where('id', $newBillId)->first();