DevForgeKit v3.0.1

First stable public release. Promotes v3.0.1-rc1 to stable after the
RC cycle's real-world verification (npm and Homebrew distribution, a
clean rc-validate run, and dogfooding on a real machine) turned up no
release-blocking issues. No code changes since v3.0.1-rc1 - see that
section below for the full release-engineering changelog (npm/Homebrew
distribution, shell completions, the release-readiness gate, and the
rest of this cycle's work).