Append a gated "Deploy to Fly.io" step to the spindle CI workflow. It runs only after format/lint/test pass, and only on a push/manual run on main (pull_request builds short-circuit). `fly deploy --remote-only` builds the Dockerfile on Fly's remote builders, so no local Docker daemon is needed and a broken production build fails the step too. flyctl authenticates via the FLY_API_TOKEN secret from spindle settings. Temporarily allows the ci/fly-deploy branch to deploy as well so the pipeline can be validated before merge (clearly marked TEMP; revert before merging). Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>