Description Add src/api/metTypes.ts (typed shape of the locationforecast compact response) and src/api/metClient.ts with a fetchCompact(lat, lon) function plus a parser into our own CityForecast shape. Truncate coordinates to 4 decimals before requesting. In development, proxy /api/met/* through Vite to api.met.no, attaching a User-Agent header server-side. Rationale MET's terms of service require every request to identify the calling application via User-Agent, which a browser fetch() cannot set itself. Dev-time proxy is the fix. MET also treats higher-precision coordinates than 4 decimals as an attempt to bypass their cache, so truncating protects us from being rate-limited or blocked.