Issue #756: honor inlined entity references on schema create-by-upload

[bjagg]

Description of Change

Problem. MDR's schema generator (schema_generation_service.add_ref) encodes a reference to another entity as an inlined object under a property key carrying a Ref infix — Ref<Child> for a plain reference, <relationship>Ref<Child> when the association has a relationship — rather than emitting an OpenAPI $ref. The create-by-upload reader only looked for $ref, so re-uploading an MDR-exported schema silently dropped every reference, and the entity-creation pass then materialized each reference as a bogus child entity.

Solution.

• Add parse_reference_key / is_inlined_reference helpers to detect the inlined-reference convention alongside genuine $ref. is_inlined_reference requires a PascalCase entity name after the marker so an embedded child merely named Reference is not misread.
• Rewrite create_reference_associations_for_children to handle both $ref and inlined references: resolve the referenced and parent entities (UniqueName from embedded metadata, falling back to the name parsed from the key — entities are created in the first pass with UniqueName defaulting to their schema-key name), and create the Placement="Reference" EntityAssociation with the correct relationship. It now receives the entity's own key name for robust parent resolution and treats a reference as a leaf (no spurious recursion into its narrowed fields).
• Skip references in create_entity_and_children_if_needed so they are no longer created as embedded child entities.

Side effects / limitations. Detection keys off the Ref infix per the issue report. That is inherently ambiguous for an entity legitimately named Ref<Something>; an in-code NOTE documents the preferred two-sided fix — have the generator stamp an explicit marker (e.g. x-lif-reference-to: <UniqueName>) and key off that instead of string-parsing the property name. Resolution assumes the uploaded schema was generated with entity metadata (the realistic export case); the key-name fallback covers the no-metadata case.

How reviewers should test. uv run pytest test/components/lif/mdr_services/test_schema_upload_service.py — covers key parsing, reference/child discrimination, relationship extraction, plain-reference (no relationship), and the embedded-child non-match. The post-pass test asserts a Reference-placement association is created with the resolved parent/child ids. End-to-end validation against a live MDR-generated schema is still worth doing before relying on this in production (see Additional Notes).

Related Issues

Closes #756

Type of Change

• Bug fix (non-breaking change which fixes an issue)

Project Area(s) Affected

• components/
• test/ or e2e/

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Checklist

• commit message follows commit guidelines (see commitlint.config.mjs)
• tests are included (unit and/or integration tests)
• code passes linting checks (uv run ruff check)
• code passes formatting checks (uv run ruff format)
• code passes type checking (uv run ty check) — no new diagnostics introduced
• pre-commit hooks have been run successfully

Testing

• Automated tests added/updated

Additional Notes

• The full mdr_services suite passes (102 tests); ty diagnostics unchanged vs main (7→7, pre-existing SQLAlchemy/pydantic library typing noise).
• This branch is independent of Issue #668: fix MDR import_datamodel reference and constraint handling #1006 (the MDR API import service method not found #668 import fix), not stacked, so it doesn't hold up that quick fix. Both touch the same region of schema_upload_service.py, so whichever merges first leaves the other a trivial conflict — Issue #668: fix MDR import_datamodel reference and constraint handling #1006 only adds a forward-looking doc comment there, which this PR replaces with the actual implementation.
• The post-pass tests use representative hand-built schema shapes. A follow-up worth adding: an end-to-end test that generates a schema via schema_generation_service and round-trips it through the upload path.

🤖 Generated with Claude Code

[bjagg]

Added the end-to-end round-trip test flagged in the description (test/bases/lif/mdr_restapi/test_schema_roundtrip.py, commit b14043f). It drives the real pipeline against a live Postgres DB: seed a source model with a Person --issuedBy(Reference)--> Organization association → generate_openapi_schema → create_data_model_from_openapi_schema, then asserts the inlined issuedByRefOrganization reference is recreated as a Reference-placement association (parent→child, relationship preserved) and not materialized as a child entity.

Verified it fails against pre-fix main: there the reference degrades to an Embedded association with no relationship. Full mdr_services suite still green; ruff/format clean.

[bjagg]

@cbeach47 — ready for review. Honors MDR's inlined Ref<Child> references on create-by-upload (unit tests + a live-Postgres generate→upload round-trip). Note: trivial conflict with #1006 in schema_upload_service.py — easiest to merge #1006 first, then this rebases cleanly (keep this PR's version).