feat: move functions to separate files

src/shared/lib/utils/roundToStepPrecision/roundToStepPrecision.ts

@@ -0,0 +1,24 @@
+import { getDecimalPlaces } from '$shared/lib/utils';
+
+/**
+ * Round a value to the precision of the given step
+ *
+ * This fixes floating-point precision errors that occur with decimal steps.
+ * For example, with step=0.05, adding it repeatedly can produce values like
+ * 1.3499999999999999 instead of 1.35.
+ *
+ * We use toFixed() to round to the appropriate decimal places instead of
+ * Math.round(value / step) * step, which doesn't always work correctly
+ * due to floating-point arithmetic errors.
+ *
+ * @param value - The value to round
+ * @param step - The step to round to (defaults to 1)
+ * @returns The rounded value
+ */
+export function roundToStepPrecision(value: number, step: number = 1): number {
+    if (step <= 0) {
+        return value;
+    }
+    const decimals = getDecimalPlaces(step);
+    return parseFloat(value.toFixed(decimals));
+}