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/isWeakMap.d.ts

@@ -0,0 +1,24 @@
+//#region src/predicate/isWeakMap.d.ts
+/**
+ * Checks if the given value is a `WeakMap`.
+ *
+ * This function tests whether the provided value is an instance of `WeakMap`.
+ * It returns `true` if the value is a `WeakMap`, and `false` otherwise.
+ *
+ * This function can also serve as a type predicate in TypeScript, narrowing the type of the argument to `WeakMap`.
+ *
+ * @param value - The value to test if it is a `WeakMap`.
+ * @returns true if the value is a `WeakMap`, false otherwise.
+ *
+ * @example
+ * const value1 = new WeakMap();
+ * const value2 = new Map();
+ * const value3 = new Set();
+ *
+ * console.log(isWeakMap(value1)); // true
+ * console.log(isWeakMap(value2)); // false
+ * console.log(isWeakMap(value3)); // false
+ */
+declare function isWeakMap(value: unknown): value is WeakMap<WeakKey, any>;
+//#endregion
+export { isWeakMap };