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/workbox-routing/setDefaultHandler.js

@@ -0,0 +1,26 @@
+/*
+  Copyright 2019 Google LLC
+
+  Use of this source code is governed by an MIT-style
+  license that can be found in the LICENSE file or at
+  https://opensource.org/licenses/MIT.
+*/
+import { getOrCreateDefaultRouter } from './utils/getOrCreateDefaultRouter.js';
+import './_version.js';
+/**
+ * Define a default `handler` that's called when no routes explicitly
+ * match the incoming request.
+ *
+ * Without a default handler, unmatched requests will go against the
+ * network as if there were no service worker present.
+ *
+ * @param {workbox-routing~handlerCallback} handler A callback
+ * function that returns a Promise resulting in a Response.
+ *
+ * @memberof workbox-routing
+ */
+function setDefaultHandler(handler) {
+    const defaultRouter = getOrCreateDefaultRouter();
+    defaultRouter.setDefaultHandler(handler);
+}
+export { setDefaultHandler };