fix cold bias reference

Author: softwareengineerprogrammer

docs/Fervo_Project_Red.md

@@ -53,7 +53,7 @@ The variance analysis (results displayed in legend captions) evaluates the predi
 Both models demonstrate high predictive fidelity, tracking steady-state flowing temperatures within 1.5°C of the empirical data.
 
 * **Overall Fit:** GEOPHIRES mathematically achieves a tighter overall fit, yielding a lower Root Mean Square Error (RMSE) and a higher coefficient of determination (R²).
-* **Systematic Bias:** The Fervo model exhibits slightly less systemic underestimation, with a cold bias of -0.50°C compared to the GEOPHIRES cold bias of -0.83°C.
+* **Systematic Bias:** The Fervo model exhibits slightly less systemic underestimation, with a cold bias of -0.50°C compared to the GEOPHIRES cold bias of -0.70°C.
 * **R² Context:** The relatively low R² values for both models are expected statistical artifacts. Because the steady-state temperature profile is essentially a flat plateau, natural sensor variance and minor reservoir oscillations account for a disproportionately large portion of the total sum of squares, suppressing the R² score despite the low absolute error.
 
 ---