Enable scroll through time with mousewheel

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

frontend/src/App.svelte

@@ -18,9 +18,16 @@
 			scrollingTimeFrameStore.next();
 		}
 	}
+	function scroll(event: WheelEvent) {
+		if (event.deltaY < 0) {
+			scrollingTimeFrameStore.next();
+		} else {
+			scrollingTimeFrameStore.prev();
+		}
+	}
 </script>
 
-<svelte:window on:keydown={keyDown} />
+<svelte:window on:keydown={keyDown} on:wheel={scroll} />
 <Toaster theme="dark" expand visibleToasts={9} />
 <template>
 	<!-- <Header /> -->

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 {