Dont display <think> tags (#496)

app/MindWork AI Studio/Chat/StringExtension.cs

@@ -0,0 +1,18 @@
+namespace AIStudio.Chat;
+
+public static class StringExtensions
+{
+    public static string RemoveThinkTags(this string input)
+    {
+        const string OPEN_TAG = "<think>";
+        const string CLOSE_TAG = "</think>";
+        if (string.IsNullOrEmpty(input) || !input.StartsWith(OPEN_TAG))
+            return input;
+        
+        var endIndex = input.IndexOf(CLOSE_TAG, StringComparison.Ordinal);
+        if (endIndex == -1)
+            return string.Empty;
+        
+        return input[(endIndex + CLOSE_TAG.Length)..];
+    }
+}