Merge pull request #56 from convertcom/feat/fullstack-v12

feat: Full Stack v12 — safe traffic ramp-up, variation preview & experiment exclusion

Merge pull request #51 from convertcom/fix/bucketing-activation-event…

…s-parity

fix: emit experience-activation (bucketing) tracking events with per-call enable_tracking control

Merge pull request #50 from convertcom/chore/semantic-release-migration

chore: migrate release pipeline to semantic-release (ruby-sdk parity)