Add glab-backed GitLab issue polling, login lookup, and comment posting so GitLab projects can be handled alongside GitHub, Gitea, and OpenProject. Also wire GitLab through SCM selection, config defaults, docs, and examples so issue #35 can be configured end to end.
GitHub rejects webhook creation when gh api serializes active as a string. Use a typed field so gh sends a real boolean, and lock the gh/gosmee integration test harness to catch regressions.
Rename the provider-aware tracker client and scope since cutoffs per provider so review-driven cleanup improves readability and avoids extra tracker fetches.