fix(frame): keep reference-valued properties as IRIs

[simontaurus]

Port of OO-LD/oold-js#3; same defect, since this module is a port of schema_to_frame.mjs.

schema_to_frame emitted no subframe for reference-valued properties, on the assumption stated in the module docstring: a referenced IRI with no local triples stays {"id": ...}. Where the target does carry triples in the same graph, framing pulls them in as an object and the framed document stops validating against the schema the frame was derived from, which declares a string there.

OOLD-EXT-68fa already requires @embed: @never here, and the worked example in the specification's #framing section already prints it, so both implementations were in breach of an existing MUST.

Reference signals: x-oold-range, an IRI-family format (the family OOLD-EXT-6ea3 recommends), or a term mapped "@type": "@id". Embedding wins where a property carries both.

keyword_alias_keys

Thing.schema.json declares id with "format": "iri" while its context aliases id to @id, so the reference signals match it. A subframe there writes {"@id": {...}} and pyld fails with "@id" value must be a string. Keys aliasing a JSON-LD keyword are excluded.

The alias is searched across the composed schema: after dereferencing, Contact keeps Thing's @context on its allOf member rather than at the root, so a root-only scan misses it. This surfaced from the committed corpus, not from a unit test, and the same fix went back into oold-js.

Verified

502 passed, 7 skipped across tests/test_validation/. Removing only the @never line fails exactly the two new framing tests, so they are not vacuous.

[github-actions]

Release preview

Merging this PR would release v1.0.1 (current: v1.0.0).

Changelog preview (truncated)

## v1.0.1 (2026-09-19)

### Bug Fixes

- **frame**: Keep reference-valued properties as IRIs
  ([`0e04a1a`](https://github.com/OO-LD/oold-python/commit/0e04a1a87b3e3db077a3f76d7252e56ee6cbf621))

### Chores

- Classify as Beta
  ([`c147a05`](https://github.com/OO-LD/oold-python/commit/c147a05f7665f1ede18f6b48c99a5c0540640d9a))

### Documentation

- **examples**: Optional children extension in wiki_data
  ([`2f372c3`](https://github.com/OO-LD/oold-python/commit/2f372c3f060fa25770b6194642db4eeca905357c))

_{Preview via python-semantic-release and conventional commits.}

[github-actions]

📊 Benchmark Results

Click to see benchmark comparison

📊 Benchmark Comparison (threshold: 1.3x)
============================================================

➖ Unchanged (within threshold):
  ➖ test_simple_dict_document_store: 0.0018s → 0.0017s (-1.3%)
  ➖ test_sqlite_document_store: 0.0019s → 0.0019s (-1.2%)
  ➖ test_local_sparql_store: 0.0319s → 0.0327s (+2.4%)
  ➖ test_oneof_subschema: 0.0541s → 0.0536s (-0.9%)
  ➖ test_enum_docstrings: 0.0459s → 0.0458s (-0.4%)
  ➖ test_subclass_inheritance: 0.0489s → 0.0504s (+3.0%)
  ➖ test_class_hierarchy: 0.0464s → 0.0461s (-0.6%)
  ➖ test_core[v1]: 0.0311s → 0.0312s (+0.2%)
  ➖ test_core[v2]: 0.0390s → 0.0387s (-0.6%)
  ➖ test_schema_generation[v1]: 0.0015s → 0.0015s (+0.4%)
  ➖ test_schema_generation[v2]: 0.0033s → 0.0034s (+2.2%)
  ➖ test_simple_json: 0.0006s → 0.0006s (-0.6%)
  ➖ test_complex_graph: 0.0014s → 0.0014s (+0.7%)

============================================================
Summary: 0 regressions, 0 improvements, 13 unchanged
============================================================

✅ No significant performance regressions

Threshold: 1.3x (30% slower triggers a regression warning)

Note: Benchmarks are informational only and won't fail the build.

_{💡 Tip: Download the benchmark-results artifact for detailed JSON data}

[codecov]

Codecov Report

❌ Patch coverage is 86.04651% with 6 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/oold/validation/frame.py	86.0%	3 Missing and 3 partials ⚠️

📢 Thoughts on this report? Let us know!

[github-actions]

📊 Benchmark Results

Click to see benchmark comparison

📊 Benchmark Comparison (threshold: 1.3x)
============================================================

➖ Unchanged (within threshold):
  ➖ test_simple_dict_document_store: 0.0020s → 0.0020s (-1.1%)
  ➖ test_sqlite_document_store: 0.0022s → 0.0021s (-1.2%)
  ➖ test_local_sparql_store: 0.0413s → 0.0407s (-1.7%)
  ➖ test_oneof_subschema: 0.0648s → 0.0651s (+0.5%)
  ➖ test_enum_docstrings: 0.0552s → 0.0557s (+0.8%)
  ➖ test_subclass_inheritance: 0.0587s → 0.0607s (+3.4%)
  ➖ test_class_hierarchy: 0.0564s → 0.0568s (+0.8%)
  ➖ test_core[v1]: 0.0392s → 0.0400s (+1.9%)
  ➖ test_core[v2]: 0.0478s → 0.0509s (+6.6%)
  ➖ test_schema_generation[v1]: 0.0017s → 0.0017s (+1.7%)
  ➖ test_schema_generation[v2]: 0.0038s → 0.0038s (-1.3%)
  ➖ test_simple_json: 0.0007s → 0.0007s (-5.4%)
  ➖ test_complex_graph: 0.0017s → 0.0016s (-6.1%)

============================================================
Summary: 0 regressions, 0 improvements, 13 unchanged
============================================================

✅ No significant performance regressions

Threshold: 1.3x (30% slower triggers a regression warning)

Note: Benchmarks are informational only and won't fail the build.

_{💡 Tip: Download the benchmark-results artifact for detailed JSON data}