feat: implement AI-driven knowledge extraction service with semantic caching and persistent storage

scratch/test_normalization.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Text.RegularExpressions;
+
+public class Program
+{
+    public static void Main()
+    {
+        string input1 = "Hello \n World";
+        string input2 = "Hello World";
+        
+        string norm1 = Normalize(input1);
+        string norm2 = Normalize(input2);
+        
+        Console.WriteLine($"Input 1: '{input1}' -> Normalized: '{norm1}'");
+        Console.WriteLine($"Input 2: '{input2}' -> Normalized: '{norm2}'");
+        Console.WriteLine($"Match: {norm1 == norm2}");
+    }
+
+    public static string Normalize(string input)
+    {
+        if (string.IsNullOrWhiteSpace(input)) return string.Empty;
+        var normalized = Regex.Replace(input.Trim(), @"\s+", " ");
+        return normalized.ToLowerInvariant();
+    }
+}