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.ConfigurationDatabase.Tests/TemplateEngineRepositoryTests.cs

@@ -221,6 +221,27 @@ public class TemplateEngineRepositoryTests : IDisposable
         Assert.Equal("Alpha", result[0].Name);
     }
 
+    /// <summary>
+    /// ScadaBridge#95: the base-only bulk variant skips derived templates that share a
+    /// requested name, while the general variant still returns them.
+    /// </summary>
+    /// <returns>A task that represents the asynchronous operation.</returns>
+    [Fact]
+    public async Task GetBaseTemplatesWithChildrenAsync_SkipsDerivedRowsSharingTheName()
+    {
+        var baseT = new Template("Alpha");
+        var derived = new Template("Alpha") { IsDerived = true };
+        var derivedOnly = new Template("Beta") { IsDerived = true };
+        _context.Templates.AddRange(baseT, derived, derivedOnly);
+        await _context.SaveChangesAsync();
+
+        var baseOnly = await _repository.GetBaseTemplatesWithChildrenAsync(new[] { "Alpha", "Beta" });
+        var all = await _repository.GetTemplatesWithChildrenAsync(new[] { "Alpha", "Beta" });
+
+        Assert.Equal(baseT.Id, Assert.Single(baseOnly).Id);
+        Assert.Equal(3, all.Count);
+    }
+
     /// <summary>Verifies that the parent template id is preserved so the inheritance chain can be walked.</summary>
     /// <returns>A task that represents the asynchronous operation.</returns>
     [Fact]