## Summary
- Added a new `build_quartz` Dagger function that builds the Quartz site from a pre-processed source tree (no towncrier)
- Reordered the release workflow so towncrier runs **once** on the runner, then passes the updated working tree to `build-quartz`
- `build_docs` and `build_changelog` are preserved for standalone use — `build_docs` now delegates to `build_quartz` internally
## Motivation
Previously towncrier ran twice per release: once inside a Dagger container (via `build_docs` → `build_changelog`) and once on the runner to capture CHANGELOG.md changes for the git commit. This was wasteful and fragile — if towncrier behavior changed, the two runs could produce different results.
## Test plan
- [ ] Review diff to confirm workflow step ordering is correct
- [ ] Trigger a release and confirm towncrier runs only once
- [ ] Verify the docs tarball contains the updated CHANGELOG.md
- [ ] `dagger call build-quartz --src=. --version=vX.Y.Z` should work standalone
Reviewed-on: https://forge.ops.eblu.me/eblume/blumeops/pulls/199