feat: enhance agent management and validation logic

- Updated AGENTS.md to clarify agent account restrictions and permissions.
- Implemented checks in AgentNodeAdminUserStoreController and AgentNodeRoleStoreController to restrict admin user and role creation to the agent's own node.
- Enhanced validation in AdminPlayerStoreController and AdminPlayerUpdateController to enforce credit limit and rebate rate rules based on player funding mode.
- Refactored various request classes to utilize shared admin account field rules for consistency.
- Improved error handling in services related to credit allocation and rebate limits to ensure proper validation and messaging.

app/Support/AdminAgentSettlementScope.php

@@ -191,7 +191,7 @@ final class AdminAgentSettlementScope
     public static function assertCanManageSitePeriods(AdminUser $admin): void
     {
         if (! self::canManageSitePeriods($admin)) {
-            abort(403, 'agent_bound_cannot_manage_periods');
+            abort(403, 'admin.agent_bound_cannot_manage_periods');
         }
     }
 
@@ -204,7 +204,7 @@ final class AdminAgentSettlementScope
     public static function assertCanPerformFinanceAdjustments(AdminUser $admin): void
     {
         if (! self::canPerformFinanceAdjustments($admin)) {
-            abort(403, 'agent_bound_cannot_finance_adjust');
+            abort(403, 'admin.agent_bound_cannot_finance_adjust');
         }
     }
 
@@ -286,12 +286,14 @@ final class AdminAgentSettlementScope
         abort_if($bill === null, 404);
 
         $actorId = self::boundAgentNodeId($admin);
-        abort_if($actorId === null, 403, 'agent_cannot_operate_bill');
+        abort_if($actorId === null, 403, 'admin.agent_cannot_operate_bill');
 
         abort_if(
             ! self::billOperableByBoundAgent($actorId, $bill),
             403,
-            (string) $bill->owner_type === 'player' ? 'agent_cannot_operate_player_bill' : 'agent_cannot_operate_bill',
+            (string) $bill->owner_type === 'player'
+                ? 'admin.agent_cannot_operate_player_bill'
+                : 'admin.agent_cannot_operate_bill',
         );
     }