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/predicate/isFinite.d.mts

@@ -0,0 +1,28 @@
+//#region src/compat/predicate/isFinite.d.ts
+/**
+ * Checks if `value` is a finite number.
+ *
+ * Acts as a type guard for `number` values — returning `true` only when `value`
+ * is of type `number` and finite (not `Infinity`, `-Infinity`, or `NaN`).
+ *
+ * @param value The value to check.
+ * @returns Returns `true` if `value` is a finite number, `false` otherwise.
+ *
+ * @example
+ * ```typescript
+ * const value1 = 100;
+ * const value2 = Infinity;
+ * const value3 = '100';
+ *
+ * console.log(isFinite(value1)); // true
+ * console.log(isFinite(value2)); // false
+ * console.log(isFinite(value3)); // false
+ *
+ * if (isFinite(value1)) {
+ *   console.log(value1.toFixed(2));
+ * }
+ * ```
+ */
+declare function isFinite(value: unknown): value is number;
+//#endregion
+export { isFinite };