Replace DOCKERHUB_USERNAME/DOCKERHUB_TOKEN with the existing org-level
secrets. Use automatic GITHUB_TOKEN for Gitea release creation.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
The image supports both RPi 5 and CM5 (same SoC/RP1), so talos-rpi5
is a better public-facing name. The internal build still produces
an installer image which gets retagged to svrnty/talos-rpi5:<tag>
in the release target.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>