Release v0.7.0

Release v0.6.0

Release v0.5.0

Release v0.4.0

Release 0.3.0 (backfilled tag)

Anchors the npm-published copperhead@0.3.0 (published 2026-07-18) to git
history. 7457be0 is the first commit where package.json reads 0.3.0; the
published tarball came from an interim working tree (cli.ts --version had
drifted to 0.1.0), which this commit reconciles.