Decide release go/no-go from unreleased binary-impacting changes.
If go, choose bump: patch|minor.

MINOR: backward-compatible, user-visible new features, and breaking-change cases.
PATCH: backward-compatible bug fixes or internal improvements.

If binary change count is 0 => should_release=false.
If binary change list empty or changelog-only => should_release=false.
If unsure between MINOR and PATCH, prefer PATCH.

Pre-1.0.0: breaking changes can be MINOR.
