Adds a configurable IIR pre-filter (beta, default 0.05, τ≈19 s at dt=1 s)
applied to theta_ist before the derivative, so stirrer-induced temperature
noise is attenuated before being amplified by differentiation rather than
after. The shared filter/derivative/post-filter logic is factored into
TempControllerBase._compute_heatrate(); both Normal and Smith subclasses
call it, replacing their duplicated inline rate blocks.
beta is read from TempCtrl.beta in the config (default 0.05 if absent) and
added to config-sim.json.tpl and config-real.json.tpl.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
jensandClaude Sonnet 4.6
5be1d4e862