fix: register a class only under the type IRIs it introduces

[simontaurus]

Problem

get_cls_iri() may read a schema $id/iri, a uuid, or the default of the type field. All three are inherited: pydantic merges json_schema_extra from the base, and a subclass that only narrows a field keeps the base's type default. Such a subclass therefore reports its parent's IRI and, being defined later, replaced the parent in _types.

Observed with generated models where a default_unit override produces a narrowing subclass:

IRI	resolved to (before)
Pressure	ProductionGasPressureUpperLimit (default millibar)
Time	DurationEqualizationAfterEvacuation
Temperature	NominalTemperature...HeatingPlates
EvacuationProcessDocumentation	EvacuationSubprocessDocumentation

Consequences: a data channel typed as Pressure resolved to a class whose default unit is millibar, so values converted to their base unit no longer matched the field default and serialization kept a redundant, non-canonical unit. Independently, loading a process documentation by IRI returned its subprocess class.

Change

Subtract the IRIs the base classes already report, so a class registers only the identity it introduces. The check stays generic: no assumption about how a hierarchy spells its identity, which keeps opensemantic's uuid convention out of oold.

Controllers are untouched: they are collected in a list and never shadow a data model.

Verification

• the four IRIs above now resolve to Pressure, Time, Temperature, EvacuationProcessDocumentation
• _types still holds 1081 entries and _controller_types 4, so no registration is lost
• 95 passed, 2 skipped (uv run --group dev pytest, excluding the panel UI suite)
• ruff check and ruff format clean

[github-actions]

Release preview

Merging this PR would release v0.16.4 (current: v0.16.3).

Changelog preview (truncated)

## v0.16.4 (2026-08-06)

### Bug Fixes

- Register a class only under the type IRIs it introduces
  ([`7ca1b85`](https://github.com/OO-LD/oold-python/commit/7ca1b85e37ed93ca2447ececfa11dc11a2265283))

### Chores

- License fix
  ([`daa8d8c`](https://github.com/OO-LD/oold-python/commit/daa8d8cfa325a3745c851c845b9fae7b5e51a0cc))

### Continuous Integration

- **release**: Add whats-changed notes with changelog link for zenodo
  ([`147d70f`](https://github.com/OO-LD/oold-python/commit/147d70fbf1c5da070f3cb9055fbe96e831fe8eaa))

- **release**: Update on title and authors
  ([`996c4de`](https://github.com/OO-LD/oold-python/commit/996c4dee6b4f07b6ec994e87cb341155a12e955c))

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

[github-actions]

📊 Benchmark Results

Click to see benchmark comparison

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

⚠️  Performance Regressions:
  ❌ test_subclass_inheritance: 0.0460s → 0.0733s (+59.4%, ratio: 1.59x)

➖ Unchanged (within threshold):
  ➖ test_simple_dict_document_store: 0.0015s → 0.0015s (+2.6%)
  ➖ test_sqlite_document_store: 0.0016s → 0.0016s (+0.1%)
  ➖ test_local_sparql_store: 0.0325s → 0.0324s (-0.5%)
  ➖ test_oneof_subschema: 0.0500s → 0.0543s (+8.5%)
  ➖ test_enum_docstrings: 0.0434s → 0.0533s (+23.0%)
  ➖ test_class_hierarchy: 0.0449s → 0.0443s (-1.2%)
  ➖ test_core[v1]: 0.0317s → 0.0346s (+9.3%)
  ➖ test_core[v2]: 0.0364s → 0.0367s (+0.7%)
  ➖ test_schema_generation[v1]: 0.0015s → 0.0015s (-1.4%)
  ➖ test_schema_generation[v2]: 0.0025s → 0.0025s (-1.7%)
  ➖ test_simple_json: 0.0006s → 0.0006s (-1.4%)
  ➖ test_complex_graph: 0.0013s → 0.0013s (+0.2%)

============================================================
Summary: 1 regressions, 0 improvements, 12 unchanged
============================================================

⚠️  Regressions detected but not failing build (informational only)

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 91.66667% with 2 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/oold/model/__init__.py	91.6%	2 Missing ⚠️

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