Adapter: Wrap LegacyWeatherSdk in a WeatherProvider

The application uses a `WeatherProvider` interface for forecasting: ```java interface WeatherProvider { double getTemperatureCelsius(String city); String getConditions(String city); // "sunny", "rainy", "cloudy", "snowy" } ``` A new third-party library, `LegacyWeatherSdk`, is the only weather data source you have access to. Its API does not match — it returns Fahrenheit and integer condition codes: ```java class LegacyWeatherSdk { public double readTempF(String location); // returns Fahrenheit public int getCondCode(String location); // 1=sunny, 2=rainy, 3=cloudy, 4=snowy } ``` You cannot change the SDK. The application code (`ForecastService`) is written against `WeatherProvider` and must not import `LegacyWeatherSdk`. Implement `LegacyWeatherAdapter` so that `LegacyWeatherSdk` can be plugged into the application as a `WeatherProvider`. After your refactor, the adapter must satisfy this contract: ```java class LegacyWeatherAdapter implements WeatherProvider { public LegacyWeatherAdapter(LegacyWeatherSdk legacy); // composition: hold the SDK, do not extend it public double getTemperatureCelsius(String city); // (F - 32) * 5 / 9 public String getConditions(String city); // 1→"sunny", 2→"rainy", 3→"cloudy", 4→"snowy", else "unknown" } ``` The validator runs three checks: 1. *translates_temperature_and_conditions* — given a `LegacyWeatherSdk` returning known Fahrenheit values (32°F, 50°F, 212°F) and codes 1-4, the adapter must return the corresponding Celsius (0°C, 10°C, 100°C) and condition strings ("sunny", "rainy", "cloudy", "snowy"). 2. *unknown_code_falls_back* — for an unrecognised code (e.g. 99), `getConditions(...)` must return `"unknown"`. Throwing or returning `null` is not acceptable; the adapter is the place where unknown legacy codes get handled. 3. *composition_and_end_to_end* — the adapter implements `WeatherProvider`; its constructor accepts a `LegacyWeatherSdk`; it does NOT extend `LegacyWeatherSdk` (composition over inheritance). A `ForecastService` wired with the adapter produces the expected forecast string end-to-end. The stub adapter throws `UnsupportedOperationException` from every method, so it fails every check until the methods are implemented.