Introduces the Merkmal-Backend-Blueprint realization model: a Merkmal
describes one distribution-independent workspace feature, a Blueprint
realizes exactly one Merkmal for exactly one backend (usually an
Ansible role applied post-first-boot via ansible-pull), and a
Bereitstellungsvorlage bundles workspace + backend + org-specific
installation directives (partitioning, encryption, secure boot).
Replaces the old flat profile model (profiles/profile.json/
distribution+version) throughout the provisioning API, data model,
interactive provisioning flow, and device enrollment docs with
templates/Bereitstellungsvorlage terminology. Moves 02-workspace-model.md
and 04-backend-model.md into architecture/, archives the superseded
flat organization-model.md.
