Refactor: standardize namespace and using directive style

Refactored all C# test files to use explicit namespace declarations and moved all using directives inside the namespace block for consistency. Updated assembly info and cache files to reflect the new build. Adjusted MvcTestingAppManifest.json to use fully qualified assembly names. No functional changes; all updates are related to code style, organization, and project metadata.

MediaBrowser.Common/Extensions/BaseExtensions.cs

@@ -2,13 +2,13 @@
 // Copyright (c) PlaceholderCompany. All rights reserved.
 // </copyright>
 
-using System;
-using System.Security.Cryptography;
-using System.Text;
-using System.Text.RegularExpressions;
-
 namespace MediaBrowser.Common.Extensions
 {
+    using System;
+    using System.Security.Cryptography;
+    using System.Text;
+    using System.Text.RegularExpressions;
+
     /// <summary>
     /// Class BaseExtensions.
     /// </summary>

MediaBrowser.Common/Extensions/HttpContextExtensions.cs

@@ -2,11 +2,11 @@
 // Copyright (c) PlaceholderCompany. All rights reserved.
 // </copyright>
 
-using System.Net;
-using Microsoft.AspNetCore.Http;
-
 namespace MediaBrowser.Common.Extensions
 {
+    using System.Net;
+    using Microsoft.AspNetCore.Http;
+
     /// <summary>
     /// Static class containing extension methods for <see cref="HttpContext"/>.
     /// </summary>

MediaBrowser.Common/Extensions/MethodNotAllowedException.cs

@@ -2,10 +2,10 @@
 // Copyright (c) PlaceholderCompany. All rights reserved.
 // </copyright>
 
-using System;
-
 namespace MediaBrowser.Common.Extensions
 {
+    using System;
+
     /// <summary>
     /// Class MethodNotAllowedException.
     /// </summary>

MediaBrowser.Common/Extensions/ProcessExtensions.cs

@@ -2,13 +2,13 @@
 // Copyright (c) PlaceholderCompany. All rights reserved.
 // </copyright>
 
-using System;
-using System.Diagnostics;
-using System.Threading;
-using System.Threading.Tasks;
-
 namespace MediaBrowser.Common.Extensions
 {
+    using System;
+    using System.Diagnostics;
+    using System.Threading;
+    using System.Threading.Tasks;
+
     /// <summary>
     /// Extension methods for <see cref="Process"/>.
     /// </summary>

MediaBrowser.Common/Extensions/ResourceNotFoundException.cs

@@ -2,10 +2,10 @@
 // Copyright (c) PlaceholderCompany. All rights reserved.
 // </copyright>
 
-using System;
-
 namespace MediaBrowser.Common.Extensions
 {
+    using System;
+
     /// <summary>
     /// Class ResourceNotFoundException.
     /// </summary>