fix: Ignore the Chain-of-Thought in AI response

Author: gadfly3173

src/Models/OpenAI.cs

@@ -13,18 +13,33 @@ namespace SourceGit.Models
     public class OpenAIChatMessage
     {
         [JsonPropertyName("role")]
-        public string Role
-        {
-            get;
-            set;
-        }
+        public string Role { get; set; }
 
         [JsonPropertyName("content")]
         public string Content
         {
-            get;
-            set;
+            get => _content;
+            set
+            {
+                // Trim leading newline characters
+                value = value.TrimStart('\n');
+
+                // Ignore the Chain-of-Thought
+                var thinkTag = "<think>";
+                var thinkEndTag = "</think>";
+                var thinkStartIndex = value.IndexOf(thinkTag, StringComparison.OrdinalIgnoreCase);
+                var thinkEndIndex = value.IndexOf(thinkEndTag, StringComparison.OrdinalIgnoreCase);
+
+                if (thinkStartIndex >= 0 && thinkEndIndex > thinkStartIndex)
+                {
+                    value = value.Substring(thinkEndIndex + thinkEndTag.Length).Trim();
+                }
+
+                _content = value;
+            }
         }
+
+        private string _content;
     }
 
     public class OpenAIChatChoice