Added a way to read what the AI received from your sources (#1100)

Co-authored-by: Thorsten Sommer <SommerEngineering@users.noreply.github.com>

app/MindWork AI Studio/Tools/Databases/IndexStore/ChunkTextHash.cs

@@ -0,0 +1,23 @@
+using System.Security.Cryptography;
+using System.Text;
+
+namespace AIStudio.Tools.Databases.IndexStore;
+
+/// <summary>
+/// The hash of the text of a chunk, exactly as it was embedded.
+/// </summary>
+/// <remarks>
+/// A vector depends on nothing but the text it was made from and the embedding signature, and all
+/// vectors of one store share that signature. So two chunks of a store with the same hash may share
+/// a vector, which is what spares a document the embedding provider for every chunk that did not
+/// change. The text is hashed with its overlap and its heading line, as the provider received it.
+/// </remarks>
+internal static class ChunkTextHash
+{
+    /// <summary>
+    /// SHA-256 over the UTF-8 bytes of the text, as lowercase hex.
+    /// </summary>
+    /// <param name="text">The text of the chunk.</param>
+    /// <returns>The hash.</returns>
+    public static string Of(string text) => Convert.ToHexStringLower(SHA256.HashData(Encoding.UTF8.GetBytes(text)));
+}