Native Cargo project graphs

Once can now read an existing Cargo.toml and turn it into a typed, cacheable build graph. Rust developers can build, run, and test a workspace without first translating it into once.toml.

Native discovery understands Cargo workspaces and the locked dependency closure from Cargo.lock, including registry, Git, and path packages. Each workspace member and locked dependency compiles as its own action, so unchanged work can be restored independently from a local or remote cache. Procedural macros and build scripts are modeled as their own targets so they rebuild only when their own inputs change.

Once keeps Cargo.toml and Cargo.lock authoritative and uses the Rust toolchain selected by the project's configuration. Test targets report their results through the same normalized shape as the other ecosystems, so scheduled runs, change-scoped selection, and summaries work the same way.

Start by running once query native-project cargo, inspect the derived targets with once query targets, then use once build, once run, and once test with the target identifiers Once reports.