@claude Create a PR with a "hello" CLI command added to the systems module that prints "Hello Berlin, it's {date and time in that city}. Hello New York, it's {equivalent}".

The string should be generated in the service, and the date/time formatting should adhere to typical localization rules at the specific place.
Let's actually make the set of cities configurable as a setting, with the default being Berlin and New York.
Let's furthermore allow to print the output as human readable, json or yaml, using some --format option