Peritheos 0.9.0

This release adds Birch–Murnaghan references to the double-Debye Helmholtz
models and optional material families for catalog browsing. Existing material
and EOS identifiers, numerical records, and flat discovery remain unchanged.

Added

• BM2, BM3, and BM4 references for both double-Debye Helmholtz models in
  Python, Rust, and .eosmat loading, with reference energies consistent
  with pressure in both absolute and reference-temperature modes.
• Optional material family metadata and curated bridgmanite, Mg–Fe monoxide,
  post-perovskite, phase D, NaAlSiO4 calcium-ferrite type, magnesite, olivine,
  and garnet families. Python provides family lookup, exact family
  filters, and grouping of catalog/search results with standalone fallback.
  Existing material identifiers, flat discovery, and EOS records are preserved.
  Python and Rust validate and round-trip the optional .eosmat family_id;
  Rust exposes Material::family_id().

Compatibility

• Python's existing Vinet double-Debye constructors remain supported, and
  .eosmat stays at format 3. Older readers cannot load the newly supported
  Birch–Murnaghan/double-Debye model combinations.
• Rust double-Debye types now accept a reference-EOS type parameter, defaulting
  to Vinet. The two corresponding ThermalModel variants hold models with
  IsothermalModel references; callers constructing or destructuring those
  variants directly must account for that type change.