feat(deploymentmanager): seam for subtree deploy — DeployAreaAsync / PreviewSubtreeDeployAsync signatures + SubtreeDeployPreview (Gitea #40)

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

@@ -1113,6 +1113,39 @@ public class DeploymentService
         return Result<SiteDeploymentSummary>.Success(summary);
     }
 
+    /// <summary>
+    /// Bulk-deploys every instance in an area subtree — the area itself plus all
+    /// of its descendant areas — with exactly the rules of
+    /// <see cref="DeploySiteAsync"/> (Disabled always skipped, up-to-date skipped
+    /// unless <paramref name="force"/>, not all-or-nothing). Gitea #40.
+    /// </summary>
+    /// <param name="areaId">The database ID of the subtree's root area.</param>
+    /// <param name="user">The username initiating the deployment.</param>
+    /// <param name="force">Deploy up-to-date instances too; never re-enables Disabled ones.</param>
+    /// <param name="cancellationToken">Cancellation token for the operation.</param>
+    /// <returns>The same per-instance result matrix as a site deploy, or a failure when the area cannot be resolved.</returns>
+    public Task<Result<SiteDeploymentSummary>> DeployAreaAsync(
+        int areaId,
+        string user,
+        bool force = false,
+        CancellationToken cancellationToken = default)
+        => throw new NotImplementedException();
+
+    /// <summary>
+    /// Cheap pre-confirm counts for a site or area subtree deploy (Gitea #40): how
+    /// many instances the subtree holds and how many of those are Disabled. A DB
+    /// read only — no staleness probe.
+    /// </summary>
+    /// <param name="siteId">The site the subtree belongs to.</param>
+    /// <param name="areaId">The subtree's root area, or null for the whole site.</param>
+    /// <param name="cancellationToken">Cancellation token for the operation.</param>
+    /// <returns>The counts, or a failure when the site or area cannot be resolved.</returns>
+    public Task<Result<SubtreeDeployPreview>> PreviewSubtreeDeployAsync(
+        int siteId,
+        int? areaId,
+        CancellationToken cancellationToken = default)
+        => throw new NotImplementedException();
+
     /// <summary>
     /// True when a bulk site deploy should leave this instance alone because the
     /// site is already running the config it would be sent.
@@ -2535,3 +2568,10 @@ public record SiteDeploymentSummary(
     int SuccessCount,
     int FailureCount,
     IReadOnlyList<SkippedInstanceResult>? SkippedInstances = null);
+
+/// <summary>
+/// Pre-confirm counts for a site or area subtree bulk deploy (Gitea #40).
+/// </summary>
+/// <param name="Total">Instances in the subtree.</param>
+/// <param name="Disabled">Of those, the Disabled ones a bulk deploy always skips.</param>
+public record SubtreeDeployPreview(int Total, int Disabled);