fix: type errors (#3)

Co-authored-by: terraputix <terraputix@mailbox.org>
Reviewed-on: useweb/open-meteo-blue#3

src/routes/weather/+layout.svelte

@@ -16,9 +16,16 @@
 
 	let { children }: Props = $props();
 
+	interface CurrentWeather {
+		current: {
+			temperature_2m: number;
+			weather_code: number;
+		};
+	}
+
 	let location = $state(get(storedLocation));
 	let mounted = $state(false);
-	let currentWeather = $state(null);
+	let currentWeather = $state<CurrentWeather | null>(null);
 
 	// Subscribe to location changes
 	storedLocation.subscribe((value) => {
@@ -47,8 +54,8 @@
 		}
 	};
 
-	const getWeatherIcon = (code) => {
-		const iconMap = {
+	const getWeatherIcon = (code: number): string => {
+		const iconMap: Record<number, string> = {
 			0: '☀️',
 			1: '🌤️',
 			2: '⛅',