feat(deployment): DeployToSiteAsync for single-site artifact deployment

Claude-Session: https://claude.ai/code/session_01MtdgwpEeCUn6cUA5f1LMPj

src/ZB.MOM.WW.ScadaBridge.DeploymentManager/ArtifactDeploymentService.cs

@@ -2,6 +2,7 @@ using System.Text.Json;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using ZB.MOM.WW.ScadaBridge.Commons.Entities.Deployment;
+using ZB.MOM.WW.ScadaBridge.Commons.Entities.Sites;
 using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Repositories;
 using ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Services;
 using ZB.MOM.WW.ScadaBridge.Commons.Messages.Artifacts;
@@ -232,6 +233,38 @@ public class ArtifactDeploymentService
         if (sites.Count == 0)
             return Result<ArtifactDeploymentSummary>.Failure("No sites configured.");
 
+        return await DeployCoreAsync(sites, user, cancellationToken);
+    }
+
+    /// <summary>
+    /// Deploys system-wide artifacts to a single site (management-API --site-id path).
+    /// </summary>
+    /// <param name="siteId">The database identifier of the target site.</param>
+    /// <param name="user">The user initiating the deployment.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>A summary of the artifact deployment result for the single site.</returns>
+    public async Task<Result<ArtifactDeploymentSummary>> DeployToSiteAsync(
+        int siteId,
+        string user,
+        CancellationToken cancellationToken = default)
+    {
+        var site = await _siteRepo.GetSiteByIdAsync(siteId, cancellationToken);
+        if (site is null)
+            return Result<ArtifactDeploymentSummary>.Failure($"Site with ID {siteId} not found.");
+
+        return await DeployCoreAsync([site], user, cancellationToken);
+    }
+
+    /// <summary>
+    /// Core deployment path shared by the all-sites and single-site entry points.
+    /// Builds a per-site command with that site's data connections and deploys to
+    /// every supplied site under one logical deployment id.
+    /// </summary>
+    private async Task<Result<ArtifactDeploymentSummary>> DeployCoreAsync(
+        IReadOnlyList<Site> sites,
+        string user,
+        CancellationToken cancellationToken)
+    {
         var deploymentId = Guid.NewGuid().ToString("N");
         var perSiteResults = new Dictionary<string, SiteArtifactResult>();
 

tests/ZB.MOM.WW.ScadaBridge.DeploymentManager.Tests/ArtifactDeploymentServiceTests.cs

@@ -233,6 +233,41 @@ public class ArtifactDeploymentServiceTests : TestKit
             Arg.Any<string>(), "retry-site", Arg.Any<object>(), Arg.Any<CancellationToken>());
     }
 
+    // ── PLAN-07 Task 4: single-site artifact deployment ──
+
+    [Fact]
+    public async Task DeployToSiteAsync_DeploysOnlyToTargetSite()
+    {
+        // Two sites exist; deploying to site 1 must build/send exactly one per-site
+        // command (for SITE1) and never touch SITE2's per-site data.
+        var site1 = new Site("Site One", "SITE1") { Id = 1 };
+        _siteRepo.GetSiteByIdAsync(1, Arg.Any<CancellationToken>()).Returns(site1);
+        var recorder = new ArtifactProbeRecorder();
+        var probe = Sys.ActorOf(Props.Create(() => new ArtifactProbeActor(recorder)));
+        var service = CreateServiceWithCommActor(probe);
+
+        var result = await service.DeployToSiteAsync(1, "tester");
+
+        Assert.True(result.IsSuccess);
+        Assert.Single(result.Value.SiteResults);
+        Assert.Equal("SITE1", result.Value.SiteResults[0].SiteId);
+        Assert.Single(recorder.Received);
+        await _siteRepo.Received(1).GetDataConnectionsBySiteIdAsync(1, Arg.Any<CancellationToken>());
+        await _siteRepo.DidNotReceive().GetDataConnectionsBySiteIdAsync(2, Arg.Any<CancellationToken>());
+    }
+
+    [Fact]
+    public async Task DeployToSiteAsync_UnknownSite_ReturnsFailure()
+    {
+        _siteRepo.GetSiteByIdAsync(999, Arg.Any<CancellationToken>()).Returns((Site?)null);
+        var service = CreateService();
+
+        var result = await service.DeployToSiteAsync(999, "tester");
+
+        Assert.True(result.IsFailure);
+        Assert.Contains("999", result.Error);
+    }
+
     private ArtifactDeploymentService CreateService()
     {
         var comms = new CommunicationService(