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/isNode.d.mts

@@ -0,0 +1,18 @@
+//#region src/predicate/isNode.d.ts
+/**
+ * Checks if the current environment is Node.js.
+ *
+ * This function checks for the existence of the `process.versions.node` property,
+ * which only exists in Node.js environments.
+ *
+ * @returns `true` if the current environment is Node.js, otherwise `false`.
+ *
+ * @example
+ * if (isNode()) {
+ *   console.log('This is running in Node.js');
+ *   const fs = import('node:fs');
+ * }
+ */
+declare function isNode(): boolean;
+//#endregion
+export { isNode };