fix(transport): case-insensitive remaining library lookups; base-only template reads for import targets (ScadaBridge#95)

- Preview matches template folders, shared scripts, external systems, SMTP
  (by Host) and SMS (by AccountSid) with the #93 ToNameLookup comparer
  (OrdinalIgnoreCase, first wins, never throws), matching SQL Server's
  case-insensitive collation, so a differently-cased target row is reported as
  a conflict instead of New.
- Apply-side in-memory lookups do the same: ApplyTemplateFoldersAsync, the
  template folder-id map, ResolveFolderParentEdgesAsync, ApplySmtpConfigsAsync
  and ApplySmsConfigsAsync. An Overwrite now updates the existing row instead of
  adding a duplicate (folder names are only unique per parent, so the old
  ToDictionary could also throw).
- New ITemplateEngineRepository.GetBaseTemplatesWithChildrenAsync filters
  IsDerived in SQL. Preview and the Overwrite load in ApplyTemplatesAsync use it,
  so a derived slot template that shares a bundled name is never the import
  target. GetTemplatesWithChildrenAsync is unchanged for the id-keyed callers
  (export closure, rewire passes), which can need derived rows.

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

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

@@ -53,8 +53,17 @@ public class TemplateEngineRepository : ITemplateEngineRepository
     }
 
     /// <inheritdoc />
-    public async Task<IReadOnlyList<Template>> GetTemplatesWithChildrenAsync(
+    public Task<IReadOnlyList<Template>> GetTemplatesWithChildrenAsync(
         IEnumerable<string> names, CancellationToken cancellationToken = default)
+        => GetTemplatesWithChildrenAsync(names, baseOnly: false, cancellationToken);
+
+    /// <inheritdoc />
+    public Task<IReadOnlyList<Template>> GetBaseTemplatesWithChildrenAsync(
+        IEnumerable<string> names, CancellationToken cancellationToken = default)
+        => GetTemplatesWithChildrenAsync(names, baseOnly: true, cancellationToken);
+
+    private async Task<IReadOnlyList<Template>> GetTemplatesWithChildrenAsync(
+        IEnumerable<string> names, bool baseOnly, CancellationToken cancellationToken)
     {
         // Bulk lookup replaces the per-name N+1 in
         // BundleImporter.PreviewAsync. Filter out null / empty / duplicate
@@ -67,7 +76,7 @@ public class TemplateEngineRepository : ITemplateEngineRepository
         if (distinct.Length == 0) return Array.Empty<Template>();
 
         return await _context.Templates
-            .Where(t => distinct.Contains(t.Name))
+            .Where(t => distinct.Contains(t.Name) && (!baseOnly || !t.IsDerived))
             .Include(t => t.Attributes)
             .Include(t => t.Alarms)
             .Include(t => t.Scripts)