feat(audit): M5.6 SourceNode sentinel backfill (purge-role) + CLI + runbook note (T5)

tests/ZB.MOM.WW.ScadaBridge.CLI.Tests/Commands/AuditCommandsScaffoldTests.cs

@@ -5,8 +5,8 @@ namespace ZB.MOM.WW.ScadaBridge.CLI.Tests.Commands;
 
 /// <summary>
 /// Scaffold tests for the <c>scadabridge audit</c> command group (Audit Log #23 M8-T1).
-/// Verifies the parent command exists with its three subcommands and that every leaf
-/// has an action wired.
+/// Verifies the parent command exists with its subcommands and that every leaf
+/// has an action wired. Updated for M5.6 T5 to cover <c>backfill-source-node</c>.
 /// </summary>
 public class AuditCommandsScaffoldTests
 {
@@ -27,11 +27,13 @@ public class AuditCommandsScaffoldTests
     }
 
     [Fact]
-    public void Audit_HasThreeSubcommands_QueryExportVerifyChain()
+    public void Audit_HasFiveSubcommands_QueryExportTreeVerifyChainBackfillSourceNode()
     {
         var audit = BuildAudit();
         var names = audit.Subcommands.Select(c => c.Name).OrderBy(n => n).ToArray();
-        Assert.Equal(new[] { "export", "query", "verify-chain" }, names);
+        Assert.Equal(
+            new[] { "backfill-source-node", "export", "query", "tree", "verify-chain" },
+            names);
     }
 
     [Fact]
@@ -48,7 +50,9 @@ public class AuditCommandsScaffoldTests
         var text = output.ToString();
         Assert.Contains("query", text);
         Assert.Contains("export", text);
+        Assert.Contains("tree", text);
         Assert.Contains("verify-chain", text);
+        Assert.Contains("backfill-source-node", text);
     }
 
     [Fact]