Add determinism tests for verdict artifact generation and update SHA256 sums script

- Implemented comprehensive tests for verdict artifact generation to ensure deterministic outputs across various scenarios, including identical inputs, parallel execution, and change ordering.
- Created helper methods for generating sample verdict inputs and computing canonical hashes.
- Added tests to validate the stability of canonical hashes, proof spine ordering, and summary statistics.
- Introduced a new PowerShell script to update SHA256 sums for files, ensuring accurate hash generation and file integrity checks.

src/Cli/StellaOps.Cli/Commands/CommandHandlers.Crypto.cs

@@ -399,7 +399,7 @@ internal static partial class CommandHandlers
             format = format,
             provider = providerName,
             timestamp = DateTimeOffset.UtcNow.ToString("O"),
-            dataHash = Convert.ToHexString(System.Security.Cryptography.SHA256.HashData(data)).ToLowerInvariant(),
+            dataHash = CryptoHashFactory.CreateDefault().ComputeHashHex(data, HashAlgorithms.Sha256),
             signature = "STUB-SIGNATURE-BASE64",
             keyId = "STUB-KEY-ID"
         };