* data: provide frequency and modem preset for meshcore
* data: provide frequency and modem preset for meshcore
* ingestor: address review comments
* fix: remove duplicate _mark_packet_seen entry from handlers __all__
* ci: install meshcore in Python workflow
protocols/meshcore.py now imports meshcore at module level (required to
fix a self-referential import failure after the providers/ → protocols/
rename). test_provider_unit.py imports that module unconditionally, so
meshcore must be present in the test environment.
* data: run black