v5.2.0

Behavior change

• CLI specs always run in a fresh empty temp directory. Previously a bare spec("x").exec("...") (no .project() / .fixture()) fell back to running in fixturesRoot itself, which meant scaffolding CLIs could pollute committed fixtures. Now every .exec() / .spawn() invocation runs in a fresh mkdtemp directory unconditionally.
• .project("name") still copies the fixture project into that temp dir first; .fixture("file") still seeds individual files on top.

This is the right default for testing scaffolding tools, code generators, bundlers, or any CLI that writes into its cwd — no more empty-project placeholder workarounds.