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/AdminSiteScope.php

@@ -77,6 +77,7 @@ final class AdminSiteScope
     {
         $codes = self::accessibleSiteCodes($admin);
         if ($codes === null) {
+            // Super admin - no site filtering
             AdminAgentScope::applyToPlayerQuery($query, $admin);
 
             return;
@@ -90,9 +91,13 @@ final class AdminSiteScope
 
         $query->whereIn('site_code', $codes);
 
-        if (AdminAgentScope::primaryAgentNode($admin) !== null) {
+        // Apply agent node filtering only for agent accounts, not platform accounts
+        $accessibleSiteIds = $admin->accessibleAdminSiteIds();
+        if ($accessibleSiteIds === null) {
+            // Agent account - apply agent node filtering
             AdminAgentScope::applyToPlayerQuery($query, $admin);
         }
+        // Platform account - no additional agent node filtering needed
     }
 
     /**