[FEATURE] Some sort of daemon for synced theme

[cy1der]

Submission checklist

• I have searched existing issues and confirmed this has not been requested before.
• I have checked existing pull requests for similar changes.

Feature type

Session / authentication

Feature summary

Sort of a half-baked idea, but it would be nice if Noctalia v5 can sync the theme with greeter without a password each time via a daemon you add as a service that handles it for you

Motivation / use case

Minimize the polkit popups for changing theme

Proposed solution

Not sure

Alternatives considered

No response

References / related projects

No response

Additional context

No response