ci: propose minor releases for breaking changes - #481

Release Please proposes a major release whenever a commit is marked as breaking, as it did with 11.0.0 in #479 after the ESM-only change in #475. We want breaking changes to ship as minor releases, and Release Please has no setting for that once a package is past 1.0.

This adds a breaking-as-minor versioning strategy and selects it in release-please-config.json. It works like the default strategy, except that a release containing breaking changes becomes a minor release. The changelog still lists them under the breaking changes heading. A Release-As: X.0.0 commit footer still releases a new major version.

fix: ...                     10.2.0 → 10.2.1
feat: ...                    10.2.0 → 10.3.0
chore!: ...                  10.2.0 → 10.3.0   (was 11.0.0)
Release-As: 11.0.0           10.2.0 → 11.0.0

🤖 Generated with Claude Code