Refactor and enhance JSON handling with extensions

Refactored `ConfigExtensions.cs` to move `ConfigurationExtensions`
to the `ReC.API.Extensions` namespace and re-added the
`GetFakeProfileId` method. Introduced `JsonExtensions.cs` with
a `JsonToDynamic` method for recursive JSON deserialization,
simplifying nested JSON handling. Updated `OutResController.cs`
and `RecActionController.cs` to use the new `JsonToDynamic`
method, improving code readability and reducing duplication.
Overall, modularized and cleaned up code for better maintainability.

src/ReC.API/Controllers/OutResController.cs

@@ -1,9 +1,8 @@
 using MediatR;
 using Microsoft.AspNetCore.Mvc;
-using ReC.API.Models;
+using ReC.API.Extensions;
 using ReC.Application.OutResults.Queries;
 using System.Net.Mime;
-using System.Text.Json;
 
 namespace ReC.API.Controllers;
 
@@ -34,8 +33,8 @@ public class OutResController(IMediator mediator, IConfiguration config) : Contr
 
         return resultType switch
         {
-            ResultType.Body => res.Body is null ? Ok(new object { }) : Ok(JsonSerializer.Deserialize<dynamic>(res.Body)),
-            ResultType.Header => res.Header is null ? Ok(new object { }) : Ok(JsonSerializer.Deserialize<dynamic>(res.Header)),
+            ResultType.Body => res.Body is null ? Ok(new object { }) : Ok(res.Body.JsonToDynamic()),
+            ResultType.Header => res.Header is null ? Ok(new object { }) : Ok(res.Header.JsonToDynamic()),
             _ => Ok(res),
         };
     }

src/ReC.API/Controllers/RecActionController.cs

@@ -1,5 +1,6 @@
 using MediatR;
 using Microsoft.AspNetCore.Mvc;
+using ReC.API.Extensions;
 using ReC.API.Models;
 using ReC.Application.RecActions.Commands;
 using ReC.Application.RecActions.Queries;

src/ReC.API/Extensions/ConfigExtensions.cs

@@ -1,6 +1,6 @@
-namespace ReC.API;
+namespace ReC.API.Extensions;
 
 public static class ConfigurationExtensions
 {
-    public static int GetFakeProfileId(this IConfiguration config) => config.GetValue<int>("FakeProfileId", 2);
+    public static int GetFakeProfileId(this IConfiguration config) => config.GetValue("FakeProfileId", 2);
 }

src/ReC.API/Extensions/JsonExtensions.cs

@@ -0,0 +1,56 @@
+using System.Text.Json;
+
+public static class JsonExtensions
+{
+    /// <summary>
+    /// Deserialize JSON string and automatically parse nested JSON strings.
+    /// </summary>
+    public static dynamic? JsonToDynamic(this string json)
+    {
+        // Deserialize the top-level JSON
+        var result = JsonSerializer.Deserialize<JsonElement>(json);
+
+        // Recursively fix stringified JSON objects
+        return JsonToDynamic(result);
+    }
+
+    private static dynamic? JsonToDynamic(JsonElement obj)
+    {
+        switch (obj.ValueKind)
+        {
+            case JsonValueKind.Object:
+                var dict = new Dictionary<string, dynamic?>();
+                foreach (var prop in obj.EnumerateObject())
+                {
+                    dict[prop.Name] = JsonToDynamic(prop.Value);
+                }
+                return dict;
+
+            case JsonValueKind.Array:
+                var list = new List<dynamic>();
+                foreach (var item in obj.EnumerateArray())
+                {
+                    list.Add(JsonToDynamic(item));
+                }
+                return list;
+
+            case JsonValueKind.String:
+                var str = obj.GetString();
+                // Try to parse string as JSON
+                if (!string.IsNullOrWhiteSpace(str) && (str.StartsWith('{') || str.StartsWith('[')))
+                {
+                    try
+                    {
+                        return JsonToDynamic(JsonSerializer.Deserialize<JsonElement>(str));
+                    }
+                    catch
+                    {
+                        return str; // Not valid JSON, return original string
+                    }
+                }
+                return str;
+            default:
+                return obj.GetRawText();
+        }
+    }
+}