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

tests/ZB.MOM.WW.ScadaBridge.Transport.IntegrationTests/Import/ImportApplyScalingTests.cs

@@ -149,7 +149,8 @@ public sealed class ImportApplyScalingTests
         return new ApplyCost(
             detectChanges,
             target.CallsTo(nameof(ITemplateEngineRepository.GetTemplateWithChildrenAsync)),
-            target.CallsTo(nameof(ITemplateEngineRepository.GetTemplatesWithChildrenAsync)),
+            target.CallsTo(nameof(ITemplateEngineRepository.GetTemplatesWithChildrenAsync))
+                + target.CallsTo(nameof(ITemplateEngineRepository.GetBaseTemplatesWithChildrenAsync)),
             result);
     }