sln build fix (again), tests fixes, audit work and doctors work

src/__Libraries/StellaOps.TestKit/TestCategories.cs

@@ -218,4 +218,33 @@ public static class TestCategories
     /// Config-diff tests: Behavioral delta tests for configuration changes.
     /// </summary>
     public const string ConfigDiff = "ConfigDiff";
+
+    // =========================================================================
+    // Distributed systems and advanced testing categories
+    // =========================================================================
+
+    /// <summary>
+    /// HLC tests: Hybrid Logical Clock distributed ordering, multi-node scenarios.
+    /// </summary>
+    public const string HLC = "HLC";
+
+    /// <summary>
+    /// Federation tests: Multi-site synchronization, cross-region replication.
+    /// </summary>
+    public const string Federation = "Federation";
+
+    /// <summary>
+    /// Latency tests: Network latency simulation, cross-region timing scenarios.
+    /// </summary>
+    public const string Latency = "Latency";
+
+    /// <summary>
+    /// Immutability tests: Artifact integrity, build reproducibility, digest verification.
+    /// </summary>
+    public const string Immutability = "Immutability";
+
+    /// <summary>
+    /// Parity tests: Competitor comparison, benchmark parity validation.
+    /// </summary>
+    public const string Parity = "Parity";
 }