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/isNil.js

@@ -0,0 +1,25 @@
+//#region src/compat/predicate/isNil.ts
+/**
+* Checks if a given value is null or undefined.
+*
+* This function tests whether the provided value is either `null` or `undefined`.
+* It returns `true` if the value is `null` or `undefined`, and `false` otherwise.
+*
+* This function can also serve as a type predicate in TypeScript, narrowing the type of the argument to `null` or `undefined`.
+*
+* @param x - The value to test for null or undefined.
+* @returns `true` if the value is null or undefined, `false` otherwise.
+*
+* @example
+* const value1 = null;
+* const value2 = undefined;
+* const value3 = 42;
+* const result1 = isNil(value1); // true
+* const result2 = isNil(value2); // true
+* const result3 = isNil(value3); // false
+*/
+function isNil(x) {
+	return x == null;
+}
+//#endregion
+exports.isNil = isNil;