// Package fakes is the umbrella for deterministic stand-ins for
// external probe binaries that Vetting's stage code normally shells
// out to (stress-ng, fio, iperf3, dmidecode, ethtool, nvidia-smi,
// mcelog, nvme). Each real binary gets its own subpackage under
// fakes/<name>/ with `package main` and a main() that prints golden
// output — build with `go build -o <tmp>/<name> ./agent/tests/fakes/<name>`
// and point a test's tests.Deps.LookPath at <tmp>/<name>.
//
// The seam in tests is tests.Deps.LookPath: when non-nil the stage
// code uses it instead of os/exec.LookPath. Outside tests, nil
// LookPath means "use the real binary on $PATH" — stages continue to
// work on production hosts without the fakes package around.
//
// How to add a new fake:
//  1. Create agent/tests/fakes/<binaryname>/main.go.
//  2. Write `package main` with a main() that prints exactly the
//     bytes the real tool would produce for the input you care to
//     simulate. Determinism > completeness — tests want a known
//     sample, not a realistic one.
//  3. Reference the fake from the unit test with `go test` compiling
//     it via t.TempDir() + `go build -o` before the test body runs.
package fakes