Automate template version upgrade

Qubes OS uses TemplateVMs as the base for most application qubes. These templates track upstream operating system releases such as Fedora and Debian, which eventually reach end-of-life and must be upgraded. Today, users generally have two options: 1. Install a fresh template and manually recreate customizations and packages. 2. Perform an in-place upgrade manually by following a multi-step process across dom0 and the template terminal. The first option is safer but discards customization. The second preserves customization but is cumbersome, error-prone, and inaccessible to many users. This project proposes an automated template version upgrade workflow built on top of Qubes OS's existing update architecture. The primary deliverable is a dom0 command-line tool that performs distro version upgrades for Fedora- and Debian-based templates while preserving safeguards, reporting progress, and leaving a clear recovery path on failure. GUI integration is a stretch goal after the CLI workflow is stable and tested.