stabilizaiton work - projects rework for maintenanceability and ui livening

src/__Libraries/StellaOps.Provcache/VeriKeyBuilder.Signer.cs

@@ -0,0 +1,52 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace StellaOps.Provcache;
+
+public sealed partial class VeriKeyBuilder
+{
+    /// <summary>
+    /// Sets the signer set hash (sorted certificate chain hashes).
+    /// </summary>
+    /// <param name="signerSetHash">The pre-computed signer set hash.</param>
+    /// <returns>This builder for fluent chaining.</returns>
+    public VeriKeyBuilder WithSignerSetHash(string signerSetHash)
+    {
+        if (string.IsNullOrWhiteSpace(signerSetHash))
+            throw new ArgumentException("Signer set hash cannot be null or empty.", nameof(signerSetHash));
+
+        _signerSetHash = NormalizeHash(signerSetHash);
+        return this;
+    }
+
+    /// <summary>
+    /// Computes signer set hash from individual certificate hashes.
+    /// Hashes are sorted lexicographically before aggregation for determinism.
+    /// </summary>
+    /// <param name="certificateHashes">Individual certificate hashes.</param>
+    /// <returns>This builder for fluent chaining.</returns>
+    public VeriKeyBuilder WithCertificateHashes(IEnumerable<string> certificateHashes)
+    {
+        ArgumentNullException.ThrowIfNull(certificateHashes);
+
+        var sortedHashes = certificateHashes
+            .Where(h => !string.IsNullOrWhiteSpace(h))
+            .Select(NormalizeHash)
+            .Order(StringComparer.Ordinal)
+            .ToList();
+
+        if (sortedHashes.Count == 0)
+        {
+            _signerSetHash = ComputeHash(Encoding.UTF8.GetBytes("empty-signer-set"));
+        }
+        else
+        {
+            var concatenated = string.Join("|", sortedHashes);
+            _signerSetHash = ComputeHash(Encoding.UTF8.GetBytes(concatenated));
+        }
+
+        return this;
+    }
+}