fix(transport): import reads the template library once per session, batches instance lookups, and expands stale instances to derived/composing templates over one flatten session (review 2026-10-21 04/P4, 08/P1, 04/C2)

src/ZB.MOM.WW.ScadaBridge.Commons/Interfaces/Repositories/ITemplateEngineRepository.cs

@@ -262,6 +262,15 @@ public interface ITemplateEngineRepository
     /// <param name="cancellationToken">Cancellation token.</param>
     /// <returns>A task that resolves to the matching instance, or <see langword="null"/> if not found.</returns>
     Task<Instance?> GetInstanceByUniqueNameAsync(string uniqueName, CancellationToken cancellationToken = default);
+    /// <summary>
+    /// Retrieves every instance whose unique name is in <paramref name="uniqueNames"/>, with the
+    /// same four child collections <see cref="GetInstanceByUniqueNameAsync"/> includes, in one
+    /// round trip (tracked). Unknown names are simply absent from the result.
+    /// </summary>
+    /// <param name="uniqueNames">The unique instance names to look up; null/empty/duplicate entries are ignored.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>A task that resolves to the matching instances.</returns>
+    Task<IReadOnlyList<Instance>> GetInstancesByUniqueNamesAsync(IEnumerable<string> uniqueNames, CancellationToken cancellationToken = default);
     /// <summary>Adds a new instance.</summary>
     /// <param name="instance">The instance to add.</param>
     /// <param name="cancellationToken">Cancellation token.</param>

src/ZB.MOM.WW.ScadaBridge.Commons/Interfaces/Transport/IStaleInstanceProbe.cs

@@ -29,4 +29,14 @@ public interface IStaleInstanceProbe
     /// <param name="cancellationToken">Cancellation token.</param>
     /// <returns>The current revision hash (e.g. <c>sha256:...</c>), or <c>null</c>.</returns>
     Task<string?> GetCurrentRevisionHashAsync(int instanceId, CancellationToken cancellationToken = default);
+
+    /// <summary>
+    /// Returns a probe for hashing a batch of instances that may share template
+    /// chains — the implementation can reuse one flatten session across the batch so
+    /// a chain is walked once, not once per instance (review 2026-10-21 04/C2). Use
+    /// the returned probe for one batch only, within the caller's scope. The default
+    /// is this probe itself (no sharing).
+    /// </summary>
+    /// <returns>A probe to use for the batch.</returns>
+    IStaleInstanceProbe BeginBatch() => this;
 }