Cross-Platform SCM Support for Scrum Helper

Scrum Helper currently only works with GitHub, leaving developers on GitLab, Bitbucket, and Gitea unable to use the tool. This project extends Scrum Helper to support these platforms by completing the existing GitLab integration, building Bitbucket Cloud support from scratch, and adding Gitea for self-hosted users. I will also implement unified error handling across all platforms and provide clear documentation for each. My approach is modular – I'll build on existing code patterns so adding more platforms later is easy. Deliverables include fully working integrations for GitLab, Bitbucket, and Gitea, consistent error handling, and complete setup guides. Gitee support is a stretch goal if time allows.