Stop warning about an empty System Composer interface dictionary

[ww-mw]

Opening an ordinary .sldd could put a banner over the tab:

One part of this file could not be read, so what you see below is incomplete.
The dictionary part "simulink/systemcomposer/interfaceDictionary.xml" holds
nothing readable, so architectural entries are reported by their Simulink class
rather than their System Composer type.

It was a false positive on a complete file, and it was raised inconsistently —
the compressed-binary reader warned where the uncompressed-text reader stayed
quiet, so the same dictionary said two different things depending on how it had
been saved. That is the "one rule, two paths" shape ScCatalog exists to close.

An empty catalog part is what MATLAB writes into any dictionary System Composer
has merely touched: built-in value types, no definitions. Nothing is lost, and
two measurements settle that the catalog-less fallback is not a degrade:

• Only Simulink.Bus is ambiguous. Over 14,668 derived entries in four real
  dictionaries, every other class is 1:1 with its classification, so IsDerived
  plus the class already yields the identical Kind. IsDerived also drives the
  Architectural-vs-Design section split on its own.
• For Simulink.Bus, the fallback IS MATLAB's answer. Strip the part from a
  dictionary holding a StructType and a DataInterface, reopen it in MATLAB
  R2027a, and both come back as Simulink.dictionary.archdata.DataInterface —
  exactly DERIVED_KIND_BY_CLASS['Simulink.Bus']. MATLAB does not regenerate the
  part on save, and it ignores simulink/ArchitecturePart.xml, which still
  records the struct type under DataTypes.

So both readers now stay silent on the same terms, whether the part is absent
(nearly every .sldd) or present and empty. With the part there, the file is
still the authority and classification is unchanged.

Tests

• scCatalog.test.ts — the binary reader over a MATLAB-shaped empty member, and
  the equality of the two formats' silence and kinds.
• parseWarnings.test.ts — the kinds either reader falls back to (all eight
  classifications), and the kinds with the catalog present.
• dataModelSources.test.ts — no .sldd reaches two layers once this warning is
  gone, so the shared-sink test now proves the contract directly: the array the
  parser filled is the array the source carries, and the node layer appends to it
  rather than replacing it.

npm run verify: 4941 passed, 26 skipped, 0 failed.