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/util/invariant.d.mts

@@ -0,0 +1,41 @@
+//#region src/util/invariant.d.ts
+/**
+ * Asserts that a given condition is true. If the condition is false, an error is thrown with the provided message.
+ *
+ * @param condition - The condition to evaluate.
+ * @param message - The error message to throw if the condition is false.
+ * @returns Returns void if the condition is true.
+ * @throws {Error} Throws an error if the condition is false.
+ *
+ * @example
+ * // This call will succeed without any errors
+ * invariant(true, 'This should not throw');
+ *
+ * // This call will fail and throw an error with the message 'This should throw'
+ * invariant(false, 'This should throw');
+ */
+declare function invariant(condition: unknown, message: string): asserts condition;
+/**
+ * Asserts that a given condition is true. If the condition is false, an error is thrown with the provided error.
+ *
+ * @param condition - The condition to evaluate.
+ * @param error - The error to throw if the condition is false.
+ * @returns Returns void if the condition is true.
+ * @throws {Error} Throws an error if the condition is false.
+ *
+ * @example
+ * // This call will succeed without any errors
+ * invariant(true, new Error('This should not throw'));
+ *
+ * class CustomError extends Error {
+ *   constructor(message: string) {
+ *     super(message);
+ *   }
+ * }
+ *
+ * // This call will fail and throw an error with the message 'This should throw'
+ * invariant(false, new CustomError('This should throw'));
+ */
+declare function invariant(condition: unknown, error: Error): asserts condition;
+//#endregion
+export { invariant };