Add payment stores

frontend/src/lib/store/lastMonthPaymentsStore.ts

@@ -0,0 +1,26 @@
+import { get, type Writable, writable } from "svelte/store";
+import { GetPaymentsForMonth } from "$wails/main/App";
+import { main } from "$wails/models";
+import { toast } from "svelte-sonner";
+import { nowStore } from "$lib/store/nowStore";
+
+async function createStore(): Promise<Writable<main.Payment[]>> {
+	const payments: main.Payment[] = [];
+	const now = new Date();
+	now.setMonth(get(nowStore).getMonth() - 1)
+	const res = await GetPaymentsForMonth(now);
+	if (!res.success) {
+		toast.error("Error getting payments " + res.error);
+	} else {
+		payments.push(...res.data);
+	}
+
+	const { subscribe, update, set } = writable(payments);
+	return {
+		subscribe,
+		update,
+		set,
+	};
+}
+
+export const lastMonthPaymentsStore = await createStore();