OS Adapters

Purpose:

• Provide a thin abstraction over package manager and service control so adding new OS families (e.g., Debian) requires minimal changes to business logic.

Coverage:

• Package commands (apt): update, install, install .deb, add PPA.
• Service control (systemd/service): enable/disable, reload/restart, daemon-reload, is-active.

Current state:

• Only Ubuntu adapter is implemented (lib/os_adapter.sh + lib/os/ubuntu.sh).
• OS support matrix is unchanged: Ubuntu 22.04/24.04, enforced by lib/platform.sh.

Extending:

• Add a new adapter file under lib/os/ (e.g., lib/os/debian.sh) and expand os_adapter_init to source it when PLATFORM_OS_ID matches.
• Keep adapters minimal and side-effect free; callers are responsible for printing/logging.