fix(vm): khôi phục lọc network khi giữ IP cho VM

reserve() không còn lấy IP ngoài network được chọn hoặc IP chưa gán network.

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

app/Services/VirtualMachine/VmIpReservationService.php

@@ -31,6 +31,7 @@ class VmIpReservationService
         return DB::transaction(function () use ($networkId, $hostId, $dns) {
             // ip_pools.status is the single source of truth for availability.
             $ipPool = $this->availableIps()
+                ->where('module_network_id', $networkId)
                 ->lockForUpdate()
                 ->inRandomOrder()
                 ->first();
@@ -48,6 +49,7 @@ class VmIpReservationService
             // module_ip_address mirrors ip_pools — update the existing synced row
             // (created when the IP was added to ip_pools) instead of inserting a new one.
             $reservation = ModuleIpAddress::where('ip', $ipPool->ip_address)
+                ->where('module_network_id', $networkId)
                 ->lockForUpdate()
                 ->first();
 
@@ -107,6 +109,7 @@ class VmIpReservationService
     private function availableIps()
     {
         return IpPool::whereIn('status', ['free', 'reserved'])
+            ->whereNotNull('module_network_id')
             ->whereNotNull('gateway')
             ->where('gateway', '!=', '');
     }