os-git-backup: automatic per system stable branch name different for each install

[BPplays]

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Is your feature request related to a problem? Please describe.
if i ever restore a new install from backup it seems a new blank repo is made and there is no way to resolve conflicts from the UI without overriding data other then changing the branch name (or remote url) manually

Describe the solution you'd like
an option to automatically pick a branch title based on a time and an id.
as an example:

• install_time = the time when opnsense was installed
• machine_id = /etc/machine-id

${install_time}_${machine_id}

would turn into:

2025-02-14_8a0e20ee95fc48d5bc6bb3cf2ff44b04

this format wouldn't need to be user configurable.

you might also need to use the time the user last restored from backup and fallback to install time, i can't remember if restoring from backup causes conflicts.

Describe alternatives you've considered
change the time whenever there is a conflict. this would also probably warrant a higher precision like 2025-02-14_0285_8a0e20ee95fc48d5bc6bb3cf2ff44b04