Adds a tuxflotte_state variable, threaded from a new
tuxflotte_auftrag_states dict in site.yml (role name -> present/absent,
populated by the agent from the checkin response's "auftraege" list,
see ADR-0010) down into each role via include_role vars. Roles not
present in that dict default to "present" via .get(), so today's
purely workspace-composed, additive-only behavior is unchanged.
Retrofits all three existing placeholder roles with the present/absent
branch as the reference implementation of the convention, and
documents it in the README for future catalog-eligible roles. This is
what makes deselecting an Auftrag actually revert something instead of
just stopping future re-application.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
