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.TemplateEngine/TemplateService.cs

@@ -1220,7 +1220,15 @@ public class TemplateService
         string user,
         CancellationToken cancellationToken = default)
     {
-        var all = await _repository.GetAllTemplatesAsync(cancellationToken) ?? Array.Empty<Template>();
+        // Every target's chain runs through templateId and on up its own chain, and the
+        // resolver is inheritance-only, so the subtree + templateId's chain is everything
+        // the resync reads (#89, reusing #86's closure). A template nobody derives from
+        // has an empty reconcile closure; it still needs its own chain to resync itself.
+        var all = await _repository.GetTemplateReconcileClosureAsync(templateId, cancellationToken)
+                  ?? Array.Empty<Template>();
+        if (all.Count == 0)
+            all = await _repository.GetTemplateChainAsync(templateId, trackChanges: true, cancellationToken)
+                  ?? Array.Empty<Template>();
         var byId = BuildTemplateLookup(all);
         if (!byId.TryGetValue(templateId, out var root))
             return Result<ResyncInheritedMembersResult>.Failure($"Template with ID {templateId} not found.");