Add optional hostname configuration using hostnamectl to global setup

[christianwhocodes]

Overview

Enhance the global setup script to optionally configure the system hostname using hostnamectl. This will help ensure consistent host identification in environments where hostname management is desired.

Details

• Integrate an optional step to set the hostname via hostnamectl within the main global setup routine.
• Document the required privileges and any system compatibility considerations (e.g., systemd-based OS).
• Make the hostname step optional, controlled via an environment variable or script flag.
• Provide example usage in setup documentation.

Acceptance Criteria

• Hostname can be configured using hostnamectl during global setup.
• The feature is optional and clearly documented.
• No impact on current setup flow if not enabled.

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If possible, include a snippet of the implementation for review or as a guide.