Add changelog fragments for V3 updates

[skyoo2003]

Description

Add changie fragments for the V3 changes delivered in PRs #256, #259, and #260.

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Refactoring (no functional changes)
• Test update

Checklist

• Tests pass (make test)
• Vet/make vet
• Linting passes (make lint)
• Build succeeds (make build)
• Documentation updated if needed
• Changelog fragment added (changie new) if this change belongs in the changelog — one sentence (two at the very most), on a single line, 400 characters max; skip for internal-only changes (CI, tests, refactors); see RELEASE.md
• Commit messages follow guidelines

Additional Notes

make all passed, and changie batch patch --dry-run rendered all three new fragments successfully.