feat: notify inquiry status changes

TaxBaik.Application/Services/IInquiryNotificationService.cs

@@ -3,4 +3,5 @@ namespace TaxBaik.Application.Services;
 public interface IInquiryNotificationService
 {
     Task NotifyCreatedAsync(int inquiryId, string name, string phone, string serviceType, string message, CancellationToken ct = default);
+    Task NotifyStatusChangedAsync(int inquiryId, string name, string phone, string serviceType, string previousStatus, string newStatus, CancellationToken ct = default);
 }

TaxBaik.Application/Services/InquiryService.cs

@@ -51,7 +51,15 @@ public class InquiryService(IInquiryRepository repository, IInquiryNotificationS
         if (!InquiryStatusMapper.TryParse(status, out var parsed))
             throw new ValidationException("지원하지 않는 문의 상태입니다.");
 
-        await repository.UpdateStatusAsync(id, InquiryStatusMapper.ToStorageValue(parsed), ct);
+        var inquiry = await repository.GetByIdAsync(id, ct);
+        if (inquiry == null)
+            return;
+
+        var previousStatus = inquiry.Status;
+        var newStatus = InquiryStatusMapper.ToStorageValue(parsed);
+
+        await repository.UpdateStatusAsync(id, newStatus, ct);
+        await notificationService.NotifyStatusChangedAsync(id, inquiry.Name, inquiry.Phone, inquiry.ServiceType, previousStatus, newStatus, ct);
     }
 
     private static int NormalizePage(int page) => Math.Max(1, page);

TaxBaik.Application/Services/NoopInquiryNotificationService.cs

@@ -4,4 +4,7 @@ public sealed class NoopInquiryNotificationService : IInquiryNotificationService
 {
     public Task NotifyCreatedAsync(int inquiryId, string name, string phone, string serviceType, string message, CancellationToken ct = default)
         => Task.CompletedTask;
+
+    public Task NotifyStatusChangedAsync(int inquiryId, string name, string phone, string serviceType, string previousStatus, string newStatus, CancellationToken ct = default)
+        => Task.CompletedTask;
 }