perf(templates): resync and resolved-members read only the chain/subtree (ScadaBridge#89)

The last two whole-library template reads are gone. Both fed the
inheritance-only TemplateInheritanceResolver, which walks one template's
parent chain and never follows compositions.

- TemplateService.ResyncInheritedMembersAsync (operator repair, CLI + editor)
  now reads #86's GetTemplateReconcileClosureAsync (derived subtree + the
  template's chain, tracked). When nothing derives from the template the
  closure is empty, so it falls back to the new tracked
  GetTemplateChainAsync - resyncing a leaf reads only its own chain.
- ManagementActor.HandleGetResolvedTemplateMembers now reads
  GetTemplateChainAsync(id, trackChanges: false): the chain alone, untracked,
  with script bodies (the resolver projects script code, so #66's body-free
  analysis closure would not be equivalent).

The chain walk is factored out of TemplateReconcileClosure into
CollectChainAsync (one load per level, stops on parent cycles and dangling
parents) and shared by both.

Evidence:
- TemplateChainReadTests (#86 fixture): for every template plus an unknown
  id, the closure-backed resync issues exactly the writes, audit row and
  result of the whole-graph resync with GetAllTemplatesAsync wired to throw;
  the resolver answers identically from the chain and the whole graph.
  17 of these fail against the old service; 13 fail with the leaf chain
  fallback removed (mutation-checked).
- TemplateChainRepositoryTests (SQLite, recorded SQL): a 4-deep chain loads
  4 templates / 8 attributes instead of 46 / 92, one split-query set per
  level, untracked on request and tracked for the resync.
- ResolvedTemplateMembersReadTests: the actor answers from the untracked
  chain read and never calls GetAllTemplatesAsync (fails on the old actor).

Claude-Session: https://claude.ai/code/session_01GT67AEHd2Acv1YPwGfXEoV

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

@@ -83,6 +83,22 @@ public interface ITemplateEngineRepository
     /// <returns>A task that resolves to the subtree followed by the template's chain.</returns>
     Task<IReadOnlyList<Template>> GetTemplateReconcileClosureAsync(int templateId, CancellationToken cancellationToken = default);
     /// <summary>
+    /// Returns the fully-loaded templates (the <see cref="GetAllTemplatesAsync"/> shape: attributes,
+    /// alarms, scripts with bodies, compositions, native alarm sources) of
+    /// <paramref name="templateId"/>'s inheritance chain only — the template, its parent,
+    /// grandparent, … (see
+    /// <see cref="ZB.MOM.WW.ScadaBridge.Commons.Types.Templates.TemplateReconcileClosure.CollectChainAsync"/>).
+    /// That is everything <c>TemplateInheritanceResolver.Resolve</c> reads for one template (Gitea #89):
+    /// it backs the read-only resolved-members query (<paramref name="trackChanges"/> = false) and the
+    /// inherited-member resync of a template with no descendants (tracked, because the resync writes
+    /// through these entities). Returns an empty list when the template does not exist.
+    /// </summary>
+    /// <param name="templateId">The template whose chain to load.</param>
+    /// <param name="trackChanges">Whether the returned entities are tracked by the context.</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>A task that resolves to the template followed by its ancestors.</returns>
+    Task<IReadOnlyList<Template>> GetTemplateChainAsync(int templateId, bool trackChanges, 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>

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

@@ -78,6 +78,44 @@ public static class TemplateReconcileClosure
 
         // 2. The root's own inheritance chain, one query per level. A level already loaded as
         //    part of the subtree means a parent cycle — the chain ends there.
+        await WalkChainAsync(templateId, loaded, result, loadByIds, cancellationToken).ConfigureAwait(false);
+        return result;
+    }
+
+    /// <summary>
+    /// Collects only the inheritance chain of <paramref name="templateId"/>: the template itself,
+    /// its parent, grandparent, … (Gitea #89). This is everything
+    /// <c>TemplateInheritanceResolver.Resolve</c> reads for one template — the resolver is
+    /// inheritance-only — so it backs the read-only resolved-members query, and the inherited-member
+    /// resync of a template nobody derives from. One <paramref name="loadByIds"/> call per level;
+    /// a parent cycle or a dangling parent edge ends the chain.
+    /// </summary>
+    /// <param name="templateId">The template whose chain to load.</param>
+    /// <param name="loadByIds">Loads the templates with the given ids (unknown ids are omitted).</param>
+    /// <param name="cancellationToken">Cancellation token.</param>
+    /// <returns>The template followed by its ancestors, each once; empty when the template is unknown.</returns>
+    public static async Task<IReadOnlyList<Template>> CollectChainAsync(
+        int templateId,
+        Func<IReadOnlyCollection<int>, CancellationToken, Task<IReadOnlyList<Template>>> loadByIds,
+        CancellationToken cancellationToken = default)
+    {
+        ArgumentNullException.ThrowIfNull(loadByIds);
+        var result = new List<Template>();
+        await WalkChainAsync(templateId, new Dictionary<int, Template>(), result, loadByIds, cancellationToken)
+            .ConfigureAwait(false);
+        return result;
+    }
+
+    // Walks templateId's parent chain upward, loading each level not already in `loaded` (one
+    // loadByIds call per level) and appending it to `result`. Ends on a repeated id (a parent
+    // cycle) or a template that does not exist (a dangling parent edge, or an unknown root).
+    private static async Task WalkChainAsync(
+        int templateId,
+        Dictionary<int, Template> loaded,
+        List<Template> result,
+        Func<IReadOnlyCollection<int>, CancellationToken, Task<IReadOnlyList<Template>>> loadByIds,
+        CancellationToken cancellationToken)
+    {
         var requested = new HashSet<int>();
         int? nextId = templateId;
         while (nextId is int id && requested.Add(id))
@@ -97,7 +135,5 @@ public static class TemplateReconcileClosure
             result.Add(template);
             nextId = template.ParentTemplateId;
         }
-
-        return result;
     }
 }