The workflows in this directory are split so that pull requests get fast, review-friendly signal while main still gets the full cross-platform verification pass.

• Required checks run against GitHub's synthetic merge commit, not the pull request head alone. This includes changes already on main and catches conflicts before they reach the branch.
• bazel.yml is the main pre-merge verification path for Rust code. It runs Bazel test and Bazel clippy on the supported Bazel targets, including the generated Rust test binaries needed to lint inline #[cfg(test)] code.
• rust-ci.yml keeps the Cargo-native PR checks intentionally small:
  • cargo fmt --check
  • cargo shear
  • argument-comment-lint on Linux, macOS, and Windows
  • tools/argument-comment-lint package tests when the lint or its workflow wiring changes

• bazel.yml also runs on pushes to main. This re-verifies the merged Bazel path and helps keep the BuildBuddy caches warm.
• rust-ci-full.yml is the full Cargo-native verification workflow. It keeps the heavier checks off the PR path while still validating them after merge:
  • the full Cargo clippy matrix
  • the full Cargo nextest matrix via per-platform archive-backed shards
  • Windows ARM64 nextest archives cross-compiled on Windows x64, then replayed on native Windows ARM64 shards
  • release-profile Cargo builds
  • cross-platform argument-comment-lint
  • Linux remote-env tests

• If a build/test/clippy check can be expressed in Bazel, prefer putting the PR-time version in bazel.yml.
• Keep rust-ci.yml fast enough that it usually does not dominate PR latency.
• Reserve rust-ci-full.yml for heavyweight Cargo-native coverage that Bazel does not replace yet.