feat: add global weather support

app/api/forecast/route.ts

@@ -1,16 +1,22 @@
 import { NextResponse } from "next/server";
 import { fetchServerForecast, parseForecastCoordinate } from "@/lib/server-forecast";
+import type { WeatherRegion } from "@/types/weather-region";
+
+function parseRegion(value: string | null): WeatherRegion {
+  return value === "GLOBAL" ? "GLOBAL" : "PL";
+}
 
 export async function GET(request: Request) {
   const { searchParams } = new URL(request.url);
   const latitude = parseForecastCoordinate(searchParams.get("latitude"), -90, 90);
   const longitude = parseForecastCoordinate(searchParams.get("longitude"), -180, 180);
+  const region = parseRegion(searchParams.get("region"));
   if (latitude === null || longitude === null) {
     return NextResponse.json({ error: "Invalid coordinates." }, { status: 400 });
   }
 
   try {
-    return NextResponse.json(await fetchServerForecast(latitude, longitude), {
+    return NextResponse.json(await fetchServerForecast(latitude, longitude, region), {
       headers: { "Cache-Control": "public, s-maxage=900, stale-while-revalidate=1800" },
     });
   } catch {