## Why
R2 publication waited for DotSlash to finish before uploading any release
assets, extending the release pipeline's critical path.
## What changed
- Start an `assets` stage after the GitHub release is created, in parallel with
DotSlash publication. Upload available assets concurrently without publishing
release metadata or channel aliases.
- Run a `finalize` stage after both jobs complete. Verify assets already present
in R2, upload any assets DotSlash added, and then publish metadata, stable
installer aliases, and release channels.
- Validate downloaded assets before upload and retain no-overwrite semantics
across both stages.
GitOrigin-RevId: 1c3e8ca715be4064c2532a5c651f1bbe03ed96a4
## What changed
- Publish the verified `release.json` metadata to `codex/channels/latest` for
stable releases and `codex/channels/prerelease` for prereleases.
- Pass the release classification through the reusable R2 workflow so GitHub
Releases and R2 channels use the same stable-versus-prerelease decision.
- Allow channel objects to be replaced while keeping versioned release objects
immutable, and verify each channel upload before completing the publication.
GitOrigin-RevId: bd5c728c5565befe42b041ee1a032b111daca1c2
## What changed
- Add a reusable workflow that runs after the GitHub Release and DotSlash publishing jobs and mirrors each release asset to a versioned R2 prefix.
- Validate GitHub asset sizes and SHA-256 digests before upload, publish objects without overwriting existing files, and verify their remote size, digest metadata, and CRC64 checksum.
- Generate `release.json` with installer-facing asset URLs and digests, then publish and verify it alongside the release assets.
- Allow an in-progress Rust release workflow to finish instead of cancelling it when another run starts.
GitOrigin-RevId: e6717cd27914994accced6e2c5df696f0e9a558e
