v2.2

Breaking changes

• Population module restructured: cosmo.py, mass.py, rate.py replaced by
  subpackages CHIMERA/population/cosmo/, mass/, rate/ with modular layout
• New likelihood API (CHIMERA/likelihood.py); existing call signatures changed
• Removed legacy example notebooks (test1dgalaxies, test1dspectral, galcat_test.h5)

New features

• PLS (Power-Law + Spline) mass model [Tagliazucchi et al. 2026, arXiv:2602.17756]
• Paired mass model structure alongside conditioned model (population/mass/)
• numpyro_utils added to CHIMERA/utils/

New examples

• complete_galaxy_catalog.ipynb
• incomplete_galaxy_catalog.ipynb
• conditioned_vs_paired_masses.ipynb
• spectral_sirens_plp.ipynb
• spectral_sirens_spline.ipynb