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/escalade/sync/index.d.ts

@@ -0,0 +1,13 @@
+declare namespace escalade {
+	export type Callback = (
+		directory: string,
+		files: string[],
+	) => string | false | void;
+}
+
+declare function escalade(
+	directory: string,
+	callback: escalade.Callback,
+): string | void;
+
+export = escalade;