feat: Introduce workflow level concurrency#311

Draft

octoper wants to merge 3 commits intoopenworkflowdev:mainfrom

octoper:vaggelis/concurrency

Commits on Feb 15, 2026

feat: Introduce worflow level concurrency
octoper
committed
feat: Enhance workflow concurrency management with validation and atomicity
octoper
committed
feat: Update workflow concurrency to support optional keys and default bucket usage
octoper
committed