src/ZB.MOM.WW.ScadaBridge.SiteRuntime/Persistence/SiteStorageService.cs

@@ -156,9 +156,22 @@ public class SiteStorageService
     /// clause so the guard is atomic with no application-level read-modify-write.
     /// </summary>
     /// <remarks>
-    /// This is the standby-node write path for replicated configs.  The active-node
-    /// apply path (<see cref="StoreDeployedConfigAsync"/>) remains unguarded and always
-    /// overwrites, because the active node's write is always authoritative.
+    /// <b>This is the reconciliation write path.</b>  <c>SiteReconciliationActor</c> runs a
+    /// per-node startup self-heal against central: it asks central what this node should be
+    /// running and fetches anything missing.  That fetch races real deploys, so the
+    /// <c>deployed_at</c> guard is what stops a slow reconcile response from overwriting a
+    /// newer config that landed while it was in flight.  The active-node apply path
+    /// (<see cref="StoreDeployedConfigAsync"/>) remains unguarded and always overwrites,
+    /// because a deploy is always authoritative.
+    /// <para>
+    /// It was originally the <i>standby</i> write path as well, under notify-and-fetch: the
+    /// standby was told a deploy had happened and fetched the config itself.  LocalDb Phase 2
+    /// replaced that with change-data-capture — the config row simply replicates — so the
+    /// standby no longer writes here at all, and last-writer-wins on the primary key (not
+    /// this guard) is what orders concurrent writes between the two nodes.  Reconciliation is
+    /// the reason the method survives; do not port the <c>deployed_at</c> guard onto the
+    /// replication path, where it would fight the HLC rather than help it.
+    /// </para>
     /// <para>
     /// <paramref name="deployedAtOverride"/> is exposed for testing so that the exact
     /// <c>deployed_at</c> value can be controlled without sleeping between calls.

tests/ZB.MOM.WW.ScadaBridge.SiteRuntime.Tests/Actors/DeploymentManagerActorTests.cs

@@ -2,6 +2,7 @@ using Akka.Actor;
 using Akka.TestKit.Xunit2;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
+using ZB.MOM.WW.ScadaBridge.Commons.Messages.Artifacts;
 using ZB.MOM.WW.ScadaBridge.Commons.Messages.Deployment;
 using ZB.MOM.WW.ScadaBridge.Commons.Messages.DebugView;
 using ZB.MOM.WW.ScadaBridge.Commons.Messages.InboundApi;
@@ -883,6 +884,87 @@ public class DeploymentManagerActorTests : TestKit, IDisposable
         Assert.Equal("SenderPump", response.InstanceUniqueName);
     }
 
+    // ── LocalDb Phase 2 / Task 12: the active-node central-only purge ──
+
+    [Fact]
+    public async Task ApplyingArtifacts_PurgesCentralOnlyNotificationConfig()
+    {
+        // Security cleanup. notification_lists and smtp_configurations can hold plaintext
+        // SMTP passwords written by a pre-2026-07-10 build, and the ACTIVE node's artifact
+        // apply is what clears them (DeploymentManagerActor.HandleDeployArtifacts). The
+        // standby's copy of this call lives in SiteReplicationActor and dies with it at
+        // Task 15, which makes this call site the ONLY remaining one.
+        //
+        // Nothing pins it today: ArtifactStorageTests covers the storage method, not the
+        // actor's call to it, so Task 16's edits to this actor could drop the call and every
+        // suite would stay green. That is precisely the kind of silent security regression
+        // this test exists to prevent — verified red-first by commenting out the call.
+        await SeedCentralOnlyRowsAsync();
+        Assert.Equal(1, await RowCountAsync("notification_lists"));
+        Assert.Equal(1, await RowCountAsync("smtp_configurations"));
+
+        var manager = CreateDeploymentManager();
+        manager.Tell(new DeployArtifactsCommand(
+            DeploymentId: "dep-purge-1",
+            SharedScripts: null,
+            ExternalSystems: null,
+            DatabaseConnections: null,
+            NotificationLists: null,
+            DataConnections: null,
+            SmtpConfigurations: null,
+            Timestamp: DateTimeOffset.UtcNow));
+
+        // The apply runs on a Task.Run inside the actor, so poll rather than assert once.
+        await AwaitPurgedAsync();
+    }
+
+    private async Task SeedCentralOnlyRowsAsync()
+    {
+        // Seeded through the service's own (already-open) LocalDb connection — a raw
+        // SqliteConnection would lack the pragmas and the zb_hlc_next() UDF the site
+        // tables' capture triggers call. Raw SQL is the only way these rows can exist at
+        // all now that the site-side write paths are gone.
+        await using var connection = _storage.CreateConnection();
+        await using var command = connection.CreateCommand();
+        command.CommandText = """
+            INSERT INTO notification_lists (name, recipient_emails, updated_at)
+                VALUES ('Ops Team', '["ops@example.com"]', @u);
+            INSERT INTO smtp_configurations
+                (name, server, port, auth_mode, from_address, username, password, oauth_config, updated_at)
+                VALUES ('smtp.example.com:587', 'smtp.example.com', 587, 'BasicAuth',
+                        'noreply@example.com', 'smtpuser', 'PLAINTEXT-SECRET', NULL, @u);
+            """;
+        command.Parameters.AddWithValue("@u", DateTimeOffset.UtcNow.ToString("O"));
+        await command.ExecuteNonQueryAsync();
+    }
+
+    private async Task<long> RowCountAsync(string table)
+    {
+        await using var connection = _storage.CreateConnection();
+        await using var command = connection.CreateCommand();
+        command.CommandText = $"SELECT COUNT(*) FROM {table}";
+        return (long)(await command.ExecuteScalarAsync())!;
+    }
+
+    private async Task AwaitPurgedAsync()
+    {
+        var deadline = DateTime.UtcNow + TimeSpan.FromSeconds(10);
+        while (DateTime.UtcNow < deadline)
+        {
+            if (await RowCountAsync("notification_lists") == 0 &&
+                await RowCountAsync("smtp_configurations") == 0)
+            {
+                return;
+            }
+
+            await Task.Delay(50);
+        }
+
+        Assert.Fail(
+            "Artifact apply did not purge the central-only notification/SMTP rows. " +
+            "The plaintext SMTP password is still on disk.");
+    }
+
     /// <summary>
     /// In-test fake <see cref="IDeploymentConfigFetcher"/>: returns a canned config JSON
     /// (notify-and-fetch success) or throws a canned exception (fetch failure), and records

tests/ZB.MOM.WW.ScadaBridge.SiteRuntime.Tests/Persistence/SiteStorageServiceTests.cs

@@ -226,7 +226,12 @@ public class SiteStorageServiceTests : IAsyncLifetime, IDisposable
         Assert.Empty(overrides);
     }
 
-    // ── Task 13: StoreDeployedConfigIfNewerAsync (guarded standby write) ──
+    // ── StoreDeployedConfigIfNewerAsync (the deployed_at-guarded write) ──
+    //
+    // Originally the standby's notify-and-fetch write path. LocalDb Phase 2 replaced that
+    // with change-data-capture, so the surviving caller is SiteReconciliationActor's
+    // startup self-heal against central, where the guard still stops a slow reconcile
+    // response from overwriting a newer config that landed while it was in flight.
 
     /// <summary>
     /// Seeds a deployed_configurations row with an explicit deployed_at timestamp using the same