refactor: resolve review comments in PR #81 (issuecomment-542)

src/NexusReader.UI.Shared/Components/MarkdownEditor.razor

@@ -17,6 +17,7 @@
 
 @code {
     private readonly string EditorId = $"milkdown-editor-{Guid.NewGuid():N}";
+    private readonly CancellationTokenSource _cts = new();
     private IJSObjectReference? _module;
     private DotNetObjectReference<MarkdownEditor>? _dotNetHelper;
 
@@ -90,11 +91,11 @@
             fileContent.Headers.ContentType = new System.Net.Http.Headers.MediaTypeHeaderValue(contentType);
             content.Add(fileContent, "file", filename);
 
-            var response = await Http.PostAsync("/api/media/upload", content);
+            var response = await Http.PostAsync("/api/media/upload", content, _cts.Token);
             if (response.IsSuccessStatusCode)
             {
                 var result = await response.Content.ReadFromJsonAsync<NexusReader.Application.DTOs.Media.UploadResultDto>(
-                    NexusReader.Application.Common.AppJsonContext.Default.UploadResultDto);
+                    NexusReader.Application.Common.AppJsonContext.Default.UploadResultDto, _cts.Token);
                 return result?.Url ?? string.Empty;
             }
             else
@@ -113,6 +114,16 @@
 
     public async ValueTask DisposeAsync()
     {
+        try
+        {
+            _cts.Cancel();
+            _cts.Dispose();
+        }
+        catch
+        {
+            // Fail silently if cancellation token disposal fails
+        }
+
         try
         {
             if (_module is not null)