Support cell-level metadata input in sccompPy

[Copilot]

sccompPy previously required pre-aggregated count tables, unlike R sccomp, which accepts cell metadata and derives counts internally.

• Input handling

  • Aggregate metadata by sample and cell_group when the configured count column is absent.
  • Support count_col as an alias for the derived count column.
  • Preserve sample-level metadata for formula evaluation while excluding cell-specific fields.

• Documentation and coverage

  • Document direct cell-metadata input.
  • Add regression coverage for aggregation, metadata retention, and schema.

estimate_res = sccompPy.sccomp_estimate(
    data=cell_metadata,
    formula_composition="~ 0 + type",
    sample="sample",
    cell_group="cell_group",
)

• Fixes allow metadata input for sccomppy #4

[stemangiola]

@zhanchen could you please review that t the API and argumente behaviour is the same as R?

[stemangiola]

@copilot have you added unit tests?

[Copilot]

@copilot have you added unit tests?

Yes. tests/test_metadata_input.py::test_sccomp_estimate_aggregates_cell_metadata covers cell-level aggregation, preservation of sample-level metadata, exclusion of cell-specific fields, and the resulting schema.