feat: add configurable wind units

app/api/notifications/subscriptions/route.ts

@@ -2,6 +2,7 @@ import { NextResponse } from "next/server";
 import { upsertPushSubscription, removePushSubscription } from "@/lib/push-store";
 import { isWebPushConfigured } from "@/lib/push-service";
 import { normalizeProvinceName } from "@/lib/provinces";
+import { DEFAULT_WIND_SPEED_UNIT, isWindSpeedUnit } from "@/lib/weather-utils";
 import type { Language } from "@/lib/i18n";
 import type { BrowserPushSubscription } from "@/types/notifications";
 
@@ -32,10 +33,12 @@ export async function POST(request: Request) {
     longitude?: unknown;
     locationName?: unknown;
     countyTeryt?: unknown;
+    windSpeedUnit?: unknown;
   } | null;
   const subscription = body?.subscription;
   const province = normalizeProvinceName(typeof body?.province === "string" ? body.province : null);
   const language: Language = body?.language === "en" ? "en" : "pl";
+  const rawWindSpeedUnit = body?.windSpeedUnit;
 
   if (!isBrowserPushSubscription(subscription) || !province) {
     return NextResponse.json({ error: "Invalid push subscription." }, { status: 400 });
@@ -54,6 +57,7 @@ export async function POST(request: Request) {
     longitude: typeof body?.longitude === "number" && Number.isFinite(body.longitude) ? body.longitude : null,
     locationName: typeof body?.locationName === "string" && body.locationName.trim() ? body.locationName.trim().slice(0, 80) : null,
     countyTeryt: typeof body?.countyTeryt === "string" && /^\d{4}$/.test(body.countyTeryt) ? body.countyTeryt : null,
+    windSpeedUnit: isWindSpeedUnit(rawWindSpeedUnit) ? rawWindSpeedUnit : DEFAULT_WIND_SPEED_UNIT,
     createdAt: now,
     updatedAt: now,
   });