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/predicate/isDate.js

@@ -0,0 +1,19 @@
+//#region src/predicate/isDate.ts
+/**
+* Checks if `value` is a Date object.
+*
+* @param value The value to check.
+* @returns Returns `true` if `value` is a Date object, `false` otherwise.
+*
+* @example
+* const value1 = new Date();
+* const value2 = '2024-01-01';
+*
+* console.log(isDate(value1)); // true
+* console.log(isDate(value2)); // false
+*/
+function isDate(value) {
+	return value instanceof Date;
+}
+//#endregion
+exports.isDate = isDate;