oaklib fails to import with linkml-runtime 1.10.0: Format.JSON removed

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## Description

Fresh install of `oaklib` via `uv tool install oaklib` fails on import due to a version skew between `linkml` 1.9.3 and `linkml-runtime` 1.10.0.

## Error

```
AttributeError: type object 'Format' has no attribute 'JSON'. Did you mean: 'JSONLD'?
```

Full traceback:

```
File "/lib/python3.12/site-packages/oaklib/__init__.py", line 8, in
from oaklib.interfaces import BasicOntologyInterface
File "/lib/python3.12/site-packages/oaklib/interfaces/__init__.py", line 1, in
from oaklib.interfaces.basic_ontology_interface import BasicOntologyInterface
File "/lib/python3.12/site-packages/oaklib/interfaces/basic_ontology_interface.py", line 14, in
from sssom.parsers import parse_sssom_table, to_mapping_set_document
File "/lib/python3.12/site-packages/sssom/__init__.py", line 13, in
from sssom.io import get_metadata_and_prefix_map
File "/lib/python3.12/site-packages/sssom/io.py", line 18, in
from linkml.validator import ValidationReport
File "/lib/python3.12/site-packages/linkml/__init__.py", line 32, in
LOCAL_METAMODEL_JSONLD_FILE = linkml_files.LOCAL_PATH_FOR(Source.META, Format.JSON)
AttributeError: type object 'Format' has no attribute 'JSON'. Did you mean: 'JSONLD'?
```

## Cause

`linkml-runtime` 1.10.0 removed or renamed `Format.JSON` from its enum, but `linkml` 1.9.3 still references it in `__init__.py`. When pip/uv resolves dependencies, it picks up the incompatible combination.

Related: linkml/linkml#3241 (same root cause — linkml/linkml-runtime version skew)

## Workaround

Pin `linkml-runtime<1.10.0`:

```bash
uv tool install oaklib --with "linkml-runtime<1.10.0"
# or
pip install oaklib "linkml-runtime<1.10.0"
```

## Suggested fix

Add an upper bound on `linkml-runtime` in oaklib's dependencies (or in sssom/linkml) until linkml releases a version compatible with linkml-runtime 1.10.0.

## Environment

- oaklib: latest (via `uv tool install oaklib`)
- linkml: 1.9.3
- linkml-runtime: 1.10.0
- Python: 3.12
- OS: Ubuntu (DigitalOcean droplet)

Reproduce the failure with a fresh `uv tool install oaklib` and inspect the import path through `oaklib/__init__.py` and `linkml/__init__.py`. Check oaklib's dependency declarations for the linkml-runtime constraint, then verify that a fresh install imports successfully without the `Format.JSON` error.

Written by the indexing model from the issue text.