v5.1.0

Features

• Directory snapshot assertion — result.directory(path).toMatchFixture(name) snapshots a generated tree against expected/{name}/. Structured diff on mismatch (added / removed / changed, with line-level diff). Update fixtures with JTERRAZZ_TEST_UPDATE=1 or vitest -u. Right idiom for scaffolding tools, code generators, bundler outputs.
• Env vars on CLI builder — spec.env({ KEY: "value" }) sets env vars on the child process. null unsets a variable. $WORKDIR expands to the temp working directory (e.g. HOME: "$WORKDIR" for full isolation). Multiple .env() calls merge.

Fixes

• Restore CI: pre-existing knip + typescript-eslint failures on main are fixed so the validate workflow passes again.