Add settings page for managing forecasting API key and URL via UI

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/node_modules/es-toolkit/dist/compat/math/round.d.mts

@@ -0,0 +1,16 @@
+//#region src/compat/math/round.d.ts
+/**
+ * Computes number rounded to precision.
+ *
+ * @param number  The number to round.
+ * @param precision The precision to round to.
+ * @returns Returns the rounded number.
+ *
+ * @example
+ * round(4.006); // => 4
+ * round(4.006, 2); // => 4.01
+ * round(4060, -2); // => 4100
+ */
+declare function round(number: number, precision?: number): number;
+//#endregion
+export { round };