feat(templates): GetTemplateStubsAsync untracked identity/edge projection

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

@@ -1,6 +1,7 @@
 using ZB.MOM.WW.ScadaBridge.Commons.Entities.Instances;
 using ZB.MOM.WW.ScadaBridge.Commons.Entities.Scripts;
 using ZB.MOM.WW.ScadaBridge.Commons.Entities.Templates;
+using ZB.MOM.WW.ScadaBridge.Commons.Types.Templates;
 
 namespace ZB.MOM.WW.ScadaBridge.Commons.Interfaces.Repositories;
 
@@ -55,6 +56,12 @@ public interface ITemplateEngineRepository
     /// <returns>A task that resolves to a read-only list of all templates without script bodies.</returns>
     Task<IReadOnlyList<Template>> GetAllTemplatesForAnalysisAsync(CancellationToken cancellationToken = default);
     /// <summary>
+    /// Returns an untracked identity/edge projection of every template (no children), ordered by name.
+    /// </summary>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>A task that resolves to a read-only list of template stubs.</returns>
+    Task<IReadOnlyList<TemplateStub>> GetTemplateStubsAsync(CancellationToken cancellationToken = default);
+    /// <summary>
     /// Database-side paged listing of templates as row summaries (child
     /// collections reduced to counts, no script bodies). Backs the
     /// <c>ListTemplates</c> management command, which previously materialised

src/ZB.MOM.WW.ScadaBridge.Commons/Types/Templates/TemplateStub.cs

@@ -0,0 +1,19 @@
+namespace ZB.MOM.WW.ScadaBridge.Commons.Types.Templates;
+
+/// <summary>
+/// Lightweight template identity/edge projection (no attributes, alarms, scripts or compositions)
+/// for callers that only need names and the inheritance/folder/ownership edges.
+/// </summary>
+/// <param name="Id">Template ID.</param>
+/// <param name="Name">Template name.</param>
+/// <param name="ParentTemplateId">Base template, if any.</param>
+/// <param name="FolderId">Containing folder, if any.</param>
+/// <param name="IsDerived">True for auto-derived composition templates.</param>
+/// <param name="OwnerCompositionId">Owning composition row for derived templates.</param>
+public sealed record TemplateStub(
+    int Id,
+    string Name,
+    int? ParentTemplateId,
+    int? FolderId,
+    bool IsDerived,
+    int? OwnerCompositionId);

src/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase/Repositories/TemplateEngineRepository.cs

@@ -90,6 +90,16 @@ public class TemplateEngineRepository : ITemplateEngineRepository
             .ToListAsync(cancellationToken);
     }
 
+    /// <inheritdoc />
+    public async Task<IReadOnlyList<TemplateStub>> GetTemplateStubsAsync(CancellationToken cancellationToken = default)
+    {
+        return await _context.Templates
+            .AsNoTracking()
+            .OrderBy(t => t.Name)
+            .Select(t => new TemplateStub(t.Id, t.Name, t.ParentTemplateId, t.FolderId, t.IsDerived, t.OwnerCompositionId))
+            .ToListAsync(cancellationToken);
+    }
+
     /// <inheritdoc />
     // Two deliberate departures from <see cref="GetAllTemplatesAsync"/>:
     // <list type="number">

tests/ZB.MOM.WW.ScadaBridge.ConfigurationDatabase.Tests/TemplateEngineRepositoryTests.cs

@@ -31,6 +31,27 @@ public class TemplateEngineRepositoryTests : IDisposable
         _context.Dispose();
     }
 
+    /// <summary>Verifies the stub projection carries identity and edges and leaves nothing tracked.</summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
+    [Fact]
+    public async Task GetTemplateStubs_ProjectsEdgesUntrackedOrderedByName()
+    {
+        var baseT = new Template("Base");
+        _context.Templates.Add(baseT);
+        await _context.SaveChangesAsync();
+        _context.Templates.Add(new Template("Alpha") { ParentTemplateId = baseT.Id });
+        await _context.SaveChangesAsync();
+        _context.ChangeTracker.Clear();
+
+        var stubs = await _repository.GetTemplateStubsAsync();
+
+        Assert.Equal(new[] { "Alpha", "Base" }, stubs.Select(s => s.Name));
+        Assert.Equal(baseT.Id, stubs[0].ParentTemplateId);
+        Assert.Null(stubs[1].ParentTemplateId);
+        Assert.False(stubs[0].IsDerived);
+        Assert.Empty(_context.ChangeTracker.Entries());
+    }
+
     /// <summary>Verifies that the topology page is bounded, filtered and returned untracked.</summary>
     /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]