fix: resolve build warnings and improve code quality

- Fix CS8600 null reference warnings by declaring nullable types
- Remove duplicate using directive for Microsoft.VisualStudio.Shell.TableManager
- Add null check for MCPServerPackage.Instance in ServerCommands
- Apply pragma suppressions for console I/O VSTHRD103 warnings
- Add project-level suppression for VSTHRD threading analyzer warnings
- Ensure consistent code style with braces on separate lines

These changes result in a clean build with 0 warnings and 0 errors.

Author: shaiku

src/CodingWithCalvin.MCPServer.Server/Program.cs

@@ -57,6 +57,7 @@
 
 static async Task RunServerAsync(string pipeName, string host, int port, string serverName, string logLevel)
 {
+#pragma warning disable VSTHRD103 // Console.Error.WriteLine is appropriate in console app context
     // Parse log level
     var msLogLevel = logLevel switch
     {
@@ -117,4 +118,5 @@ static async Task RunServerAsync(string pipeName, string host, int port, string
     await app.RunAsync();
 
     Console.Error.WriteLine("Server shutdown complete");
+#pragma warning restore VSTHRD103
 }

src/CodingWithCalvin.MCPServer.Server/RpcClient.cs

@@ -96,8 +96,10 @@ public Task<List<ToolInfo>> GetAvailableToolsAsync()
 
     public Task ShutdownAsync()
     {
+#pragma warning disable VSTHRD103 // Console.Error.WriteLine is fine in console app context
         Console.Error.WriteLine("Shutdown requested via RPC");
         _shutdownCts.Cancel();
+#pragma warning restore VSTHRD103
         return Task.CompletedTask;
     }
 

src/CodingWithCalvin.MCPServer/CodingWithCalvin.MCPServer.csproj

@@ -5,6 +5,8 @@
     <LangVersion>latest</LangVersion>
     <Nullable>enable</Nullable>
     <RootNamespace>CodingWithCalvin.MCPServer</RootNamespace>
+    <!-- Suppress VS-Threading analyzer warnings that are architectural decisions or false positives in VSIX context -->
+    <NoWarn>$(NoWarn);VSTHRD002;VSTHRD003;VSTHRD010;VSTHRD110;VSSDK007</NoWarn>
   </PropertyGroup>
 
   <ItemGroup>

src/CodingWithCalvin.MCPServer/Commands/ServerCommands.cs

@@ -154,6 +154,11 @@ private static void OnShowTools(object sender, EventArgs e)
         {
             await ThreadHelper.JoinableTaskFactory.SwitchToMainThreadAsync();
 
+            if (MCPServerPackage.Instance == null)
+            {
+                return;
+            }
+
             if (MCPServerPackage.RpcServer == null || !MCPServerPackage.RpcServer.IsConnected)
             {
                 VsShellUtilities.ShowMessageBox(

src/CodingWithCalvin.MCPServer/Services/VisualStudioService.cs

@@ -16,10 +16,8 @@
 using Microsoft.VisualStudio.Shell;
 using Microsoft.VisualStudio.Shell.Interop;
 using Microsoft.VisualStudio.Shell.TableManager;
-using Microsoft.VisualStudio.Text.Editor;
-
 using Microsoft.VisualStudio.Shell.TableControl;
-using Microsoft.VisualStudio.Shell.TableManager;
+using Microsoft.VisualStudio.Text.Editor;
 
 namespace CodingWithCalvin.MCPServer.Services;
 
@@ -1510,7 +1508,7 @@ public async Task<ErrorListResult> GetErrorListAsync(string? severity = null, in
             }
 
             // Cast to IErrorList to access the TableControl
-            IErrorList errorList = errorListService as IErrorList;
+            IErrorList? errorList = errorListService as IErrorList;
             if (errorList == null)
             {
                 result.Items.Add(new ErrorItemInfo
@@ -1702,7 +1700,7 @@ public async Task<OutputReadResult> ReadOutputPaneAsync(string paneIdentifier)
             }
 
             // Find the matching pane by name (works for both well-known and custom panes)
-            EnvDTE.OutputWindowPane targetPane = null;
+            EnvDTE.OutputWindowPane? targetPane = null;
 
             foreach (EnvDTE.OutputWindowPane outputPane in dte.ToolWindows.OutputWindow.OutputWindowPanes)
             {