Remove config calls from internal functions and expose only at interf…

[nicoloesch]

• Fixes Refactor: move config reads out of dataclasses and algorithmic functions #30

Notes

Depends on omop-emb to pass: AustralianCancerDataNetwork/omop-emb#50. (The reason the typer fails).
Requires version bump in pyproject.toml to 2.0 for omop-emb.

Summary

OmopGraphConfig.get_config()/OmopEmbConfig.get_config() were being called deep inside graph-traversal functions and a dataclass field default instead of once at a caller-resolved boundary.

• find_shortest_paths, find_shortest_paths_batch, find_standard_paths (graph/paths.py) revert max_depth/max_paths/max_concepts to literal defaults, removing OmopGraphConfig from this module entirely.
• GroundingConstraints.max_depth (reasoning/grounding.py) was an unguarded default_factory reachable with zero exception handling from oaklib_interface/omop_implementation.py:314 (an external OAK adapter entry point). Same fix: literal default instead of a config read.
• KnowledgeGraph.emb property (graph/kg.py) updated for the new omop-emb resolve_backend(backend_type, *, sqlite_path=...) signature, and its own config resolution pushed up to EmbeddingConfiguration construction rather than the property re-resolving on first access.

[nicoloesch]

Closing in favor of absorbing this into #34.

Depends on AustralianCancerDataNetwork/omop-emb#50, which is being absorbed the same way (see that PR). Merging this chain independently first would mean two breaking releases in quick succession instead of one.

The config-boundary fixes here (paths.py, grounding.py, kg.py) are being adopted as designed.