Default display to last month

Since we pay bills for the last month in the current month...

frontend/src/lib/store/scrollingTimeFrameStore.ts

@@ -4,7 +4,8 @@ import { type Writable, writable } from "svelte/store";
 async function createStore(): Promise<Writable<ScrollingTimeframe> & { next: Function; prev: Function }> {
 	const thism = new Date();
 	const lastm = new Date();
-	lastm.setMonth(thism.getMonth() - 1);
+	thism.setMonth(thism.getMonth() - 1);
+	lastm.setMonth(lastm.getMonth() - 2);
 
 	const { subscribe, update, set } = writable({ from: lastm, to: thism });
 	return {