fix: Resolve TypeScript errors

Signed-off-by: Hermes Agent <hermes@nosuchhost>

client/node_modules/lib0/statistics.js

@@ -0,0 +1,19 @@
+/**
+ * Utility helpers for generating statistics.
+ *
+ * @module statistics
+ */
+
+import * as math from './math.js'
+
+/**
+ * @param {Array<number>} arr Array of values
+ * @return {number} Returns null if the array is empty
+ */
+export const median = arr => arr.length === 0 ? NaN : (arr.length % 2 === 1 ? arr[(arr.length - 1) / 2] : (arr[math.floor((arr.length - 1) / 2)] + arr[math.ceil((arr.length - 1) / 2)]) / 2)
+
+/**
+ * @param {Array<number>} arr
+ * @return {number}
+ */
+export const average = arr => arr.reduce(math.add, 0) / arr.length