The commit rephrases the README to focus on Cloud-Init setup and removes
unused Ansible code, making Tailscale configuration automatic.
Subject line: Replace Ansible with automated Cloud-Init configuration
Body: Refactors infrastructure bootstrapping to leverage Cloud-Init
instead of Ansible for initial VM setup, particularly with respect to
Tailscale installation and authentication.
This simplifies the architecture by: - Removing manual post-provisioning
Ansible steps - Automating Tailscale setup via Cloud-Init - Updating
documentation to reflect new workflow
