Changes to pydantic model validation and dict casting related to pydantic 2.9 upgrade; tests still not passing

Advanced to pydantic 2.*
Relaxed python and pytorch versions

Reorganized with namespace packages

See merge request !5

Moved phenobase references to svlt-pheno; session-persistent phenobase is in its own singleton object

Core tests pass (still iffy on API ones with server), now with core modules in top level svlt.* namespace (no longer need svlt.core.*)

Prototyped namespace package tree: https://packaging.python.org/en/latest/guides/packaging-namespace-packages/

Build config only

See merge request rhodes/model_server!103

Merge staging as release

See merge request rhodes/model_server!102

Dev batch runner stats

See merge request rhodes/model_server!101