Fix build and code structure improvements. New but essential UI functionality. CI improvements. Documentation improvements. AI module improvements.

src/Findings/StellaOps.Findings.Ledger/Services/Attachments/AttachmentEncryptionService.cs

@@ -42,7 +42,7 @@ public sealed class AttachmentEncryptionService : IAttachmentEncryptionService
         var nonce = RandomNumberGenerator.GetBytes(12);
         var ciphertext = new byte[plaintext.Length];
         var tag = new byte[16];
-        using var aes = new AesGcm(masterKey);
+        using var aes = new AesGcm(masterKey, 16); // Specify tag size for AES-256-GCM
         aes.Encrypt(nonce, plaintext, ciphertext, tag);
 
         return new AttachmentEncryptionResult(