fix: CRM 다이얼로그의 ClientId 바인딩을 Nullable int? 로 변경하고 CompanyName null 대비 Fallback 이름을 Name으로 매핑하여 MudSelect 초기 렌더링 Circuit 크래시 원천 차단

TaxBaik.Web/Components/Admin/Pages/Contracts.razor

@@ -107,10 +107,10 @@
     </TitleContent>
     <DialogContent>
         <MudForm @ref="form">
-            <MudSelect T="int" @bind-Value="contractForm.ClientId" Label="고객" Required="true" Variant="Variant.Outlined" FullWidth="true" Class="mb-4">
+            <MudSelect T="int?" @bind-Value="contractForm.ClientId" Label="고객" Required="true" Variant="Variant.Outlined" FullWidth="true" Class="mb-4" RequiredError="고객을 선택하세요.">
                 @foreach (var client in clients)
                 {
-                    <MudSelectItem Value="@client.Id">@client.CompanyName</MudSelectItem>
+                    <MudSelectItem Value="@((int?)client.Id)">@(string.IsNullOrEmpty(client.CompanyName) ? client.Name : client.CompanyName)</MudSelectItem>
                 }
             </MudSelect>
             <MudTextField T="string" @bind-Value="contractForm.ContractNumber" Label="계약번호" Variant="Variant.Outlined" FullWidth="true" Class="mb-4" Required="true" />
@@ -180,7 +180,7 @@
     {
         contractForm = new ContractForm
         {
-            ClientId = clients.FirstOrDefault()?.Id ?? 0,
+            ClientId = clients.FirstOrDefault()?.Id,
             StartDate = DateTime.Today
         };
         isDialogOpen = true;
@@ -200,8 +200,9 @@
 
         try
         {
+            if (contractForm.ClientId == null) return;
             var newId = await ContractClient.CreateAsync(
-                contractForm.ClientId,
+                contractForm.ClientId.Value,
                 contractForm.ContractNumber,
                 contractForm.ServiceType,
                 contractForm.StartDate ?? DateTime.Now,
@@ -254,7 +255,7 @@
 
     private class ContractForm
     {
-        public int ClientId { get; set; }
+        public int? ClientId { get; set; }
         public string ContractNumber { get; set; } = "";
         public string ServiceType { get; set; } = "";
         public DateTime? StartDate { get; set; }