2.2.0

• Added inline type hints across the public API and a py.typed marker
  (PEP 561), so downstream type-checkers pick up thermofeel's signatures
• Exported fahrenheit_to_celsius at the top level, completing the C/K/F
  converter set
• Fixed silent integer-dtype truncation in
  calculate_saturation_vapour_pressure_multiphase and approximate_dsrp: an
  integer-typed input array no longer truncates the float result
• Added the missing citation for calculate_relative_humidity_percent
  (Magnus-Tetens; Murray 1967) and documented validity ranges in the UTCI, wet
  bulb, simple WBGT, NET, apparent-temperature and humidex docstrings; documented
  the array calling convention and that relative humidity is not clamped
• calculate_bgt (and therefore the Stull calculate_wbgt) now returns the
  mean radiant temperature at exactly zero wind — the analytic calm-air limit
  (no convection ⇒ globe at radiative equilibrium) — instead of NaN. Values for
  any positive wind are unchanged
• Ran a first numerical-robustness pass (ROBUSTNESS.md): audited the
  log/sqrt/power/division domains and added NaN-propagation and
  error-contract tests
• The published wheel now ships only the thermofeel package (examples/,
  scripts/ and tests/ are no longer packaged)
• Raised the minimum supported Python to 3.10 (requires-python = ">=3.10"),
  refreshed the trove classifiers and added Python 3.14
• Repaired the examples/compute-thermal-indices.py example to the 2.x API:
  solar geometry now obtained from earthkit-meteo
  (solar.cos_solar_zenith_angle_integrated), calculate_utci/calculate_wbgt/
  calculate_bgt/calculate_normal_effective_temperature return Kelvin directly,
  renamed/removed functions and the obsolete timing decorators dropped
• Removed dead, overwritten code in scale_windspeed (kept the computed log-law
  coefficient) and corrected the approximate_dsrp threshold comment
• Added the thermofeel.excess_heat submodule: Excess Heat Factor (EXHF),
  Excess Cold Factor (EXCF), heatwave severity, and the supporting daily mean
  temperature, significance and acclimatisation indices, after Nairn & Fawcett
  (2014). The factors are also exposed at the top level as
  calculate_excess_heat_factor / calculate_excess_cold_factor. The functions
  implement the per-day formulas; the temporal aggregations are left to upstream
  tooling (e.g. earthkit-transforms)
• Added calculate_wbgt_liljegren: physically based Wet Bulb Globe Temperature
  using the Liljegren et al. (2008) method, validated against Liljegren's
  reference implementation (github.com/mdljts/wbgt)
• Added calculate_wind_speed_2m_liljegren: the KNMI/Liljegren
  stability-dependent 10 m-to-2 m wind-speed profile, used by default in
  calculate_wbgt_liljegren (selectable via its wind_scaling argument)
• Added calculate_heat_force: the KNMI 0–10 heat-force (hittekracht) scale
  derived from WBGT (KNMI Technical Report TR-26-04)
• Removed the broken, unexported experimental_wbgt module, now superseded by
  calculate_wbgt_liljegren
• Fixed the calculate_bgt argument order in the scalar test suite