feat: ApiResponse<T> 공통 응답 포맷 구현 (#14)

Reviewed-on: https://git.ipstein.myds.me/SPMS/SPMS_API/pulls/15

SPMS.Domain/Common/ApiResponse.cs

@@ -0,0 +1,33 @@
+using System.Text.Json.Serialization;
+
+namespace SPMS.Domain.Common;
+
+public class ApiResponse
+{
+    [JsonPropertyName("result")]
+    public bool Result { get; init; }
+
+    [JsonPropertyName("code")]
+    public string Code { get; init; } = ErrorCodes.Success;
+
+    [JsonPropertyName("msg")]
+    public string Msg { get; init; } = string.Empty;
+
+    public static ApiResponse Success()
+        => new() { Result = true, Code = ErrorCodes.Success };
+
+    public static ApiResponse Fail(string code, string msg)
+        => new() { Result = false, Code = code, Msg = msg };
+}
+
+public class ApiResponse<T> : ApiResponse
+{
+    [JsonPropertyName("data")]
+    public T? Data { get; init; }
+
+    public static ApiResponse<T> Success(T data)
+        => new() { Result = true, Code = ErrorCodes.Success, Data = data };
+
+    public new static ApiResponse<T> Fail(string code, string msg)
+        => new() { Result = false, Code = code, Msg = msg };
+}