Add doc to script file

src/utils/calculations.ts

@@ -1,3 +1,14 @@
+/**
+ * Pharmacokinetic Calculation Utilities
+ *
+ * Combines multiple dose profiles over time to create complete concentration
+ * curves. Handles steady-state calculations, dose accumulation, and empty
+ * value filtering for robust simulation.
+ *
+ * @author Andreas Weyer
+ * @license MIT
+ */
+
 import { timeToMinutes } from './timeUtils';
 import { calculateSingleDoseConcentration } from './pharmacokinetics';
 import type { Dose, Deviation, SteadyStateConfig, PkParams, ConcentrationPoint } from '../constants/defaults';