[Add] Vendor Sirius + GMF ecore metamodels with ECoreNetto validation (closes #51)

[samatstariongroup]

Closes #51 (Phase A of the .aird support epic #50).

Vendors the Sirius + GMF Ecore metamodels behind the .aird diagram/representation format and
proves ECoreNetto loads them fully resolved — the input for generating the .aird object model
(#52). No production code; vendoring + validation + docs only.

What's here

• resources/ecore-sirius/ — 5 vendored .ecore files (EPL-2.0) with LICENSE-EPL-2.0.md
  and a provenance README.md:
  • viewpoint.ecore, diagram.ecore, sequence.ecore, table.ecore — eclipse-sirius/sirius-desktop v7.6.0
  • notation.ecore — eclipse-gmf-runtime/gmf-notation 9655137
  • Declared nsURIs match the TestData/**/*.aird fixtures exactly (viewpoint/diagram/table 1.1.0, sequence 2.0.0, GMF notation 1.0.3).
• NOTICE — extended with the Sirius (4) and GMF (5) third-party entries.
• docs/sirius-metamodel-inventory.md — 20 packages across the 5 files; the per-package
  EClass/EEnum/EDataType table (source of truth for the test) and the dependency graph.
• docs/sirius-ecorenetto-validation.md — the verdict + how it's proven.
• Auriga.CodeGenerator.Tests/SiriusMetamodelValidationTestFixture.cs — 6 regression tests
  mirroring the Capella harness; the test csproj copies resources/ecore-sirius/*.ecore to
  Data/ecore-sirius/.

Modifications to the upstream ecores (documented in the README/NOTICE)

1. Cross-file reference paths rewritten to self-contained form (same as the Capella set):
   ../../.../X.ecore#... → X.ecore#..., and Ecore platform:/plugin/... refs →
   http://www.eclipse.org/emf/2002/Ecore#....
2. Removed 10 documentation-only TagValues deprecation-marker annotations in diagram.ecore
   whose references point into another file's EAnnotation detail entries
   (viewpoint.ecore#//%Tags%/@details.N) — a fragment form ECoreNetto cannot resolve. No
   EClass, feature, supertype, or enumeration affected.

Validation

SiriusMetamodelValidationTestFixture asserts, against a single ECoreNetto ResourceSet:

• 5/5 files load with 0 diagnostics
• counts match the inventory: 20 packages, 454 EClass, 39 EEnum, 12 EDataType
• 0 unresolved supertypes/feature types (520 supertype + 959 feature-type refs)
• cross-file inheritance resolves (diagram/table/sequence → viewpoint; sequence → diagram)
• eOpposite 28 declared = 28 resolved, all mutual
• annotations preserved

Full Auriga.CodeGenerator.Tests suite: 84 passed, 0 failed (6 new + existing Capella/scaffold
tests unaffected — the Capella 21-file assertions are untouched since the Sirius files live in a
separate directory).

[github-actions]

Package	Line Rate	Branch Rate	Complexity	Health
Auriga	38%	54%	15574	❌
Auriga.CodeGenerator	90%	77%	404	✔
Auriga.Extensions	97%	88%	48	✔
Auriga.Reporting	0%	0%	12	❌
Auriga.Xmi	25%	13%	40507	❌
Summary	28% (27148 / 96125)	22% (10771 / 49070)	56545	❌

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud