[afourniernv]

What

Add a separate WASM job to the Go validation workflow. Build the guest, run tests and vet with CGO_ENABLED=0, then run the WASM tests with Go race detection.

Why

The default WASM backend needs explicit coverage without cgo. Separate native and WASM jobs make failures easier to identify.

How tested

Checked the refreshed stack locally with Go 1.26.2 on macOS arm64:

• Locked native release and WASI guest builds passed using the direct Cargo commands.
• Go tests and vet passed for all four cgo/build-tag combinations. Cgo-enabled tests used race detection; native tests also used GOEXPERIMENT=cgocheck2 and a forced rebuild.
• Both the missing-startup-export and cancellation-before-outcome regression tests passed.
• Native builds exclude wazero and the embedded guest.
• Actionlint, Ruff, mypy, and 177 Python tests passed. Python tests excluded integration tests and reused a native extension with matching Python/PyO3 sources.

Native links emitted local macOS deployment-target warnings; tests passed. No live provider calls or publishing. GitHub checks run separately.

Notes for reviewers

Stacked on #1147, which adds Go backend reporting. Still a draft.

The guest build commands are inlined in this workflow and documented in the README. Validation only: no artifact uploads, releases, or publishing. The Go version comes from go.mod.

Adapted from Nick DiZazzo's dual-engine contribution. His original PR and branch are unchanged.