Time-aligned overlayfreq offset (left, blue) · room temp (right, red)
freq is decimated min/max · room temp at full 10 s resolution
Δfreq vs ΔTscatter + linear fit
6,591 resampled pairs · slope = -0.017 Hz/°C
Residuals after linear fitν − (a·T + b) vs time
σ_residual = 0.0020 Hz · structure here = nonlinear effects (lag, hysteresis)