* fix(conversion): load .mlpackage instead of unloadable .mlmodelc
The native ct.models.MLModel runtime added in the diffusers conversion
path cannot load compiled .mlmodelc directories (no Manifest.json), so
the converter's compiled output failed at load with "A valid manifest
does not exist". Both converters now return the .mlpackage directly and
the loader lists only .mlpackage. Removes the now-dead coremlcompiler
wrappers.
* chore(release): bump version to 2.0.1