A preview deployment set COOLIFY_BRANCH in three places with three
values: the Compose shell variables used the application branch
(main), the Compose parser used pull/<id>/head, and other build packs
used the fetched refspec (pull/<id>/head:pr-<id>-coolify) or the
application branch. A variable that refers to ${COOLIFY_BRANCH} then
got a different value than the container. All paths now use
Application::coolifyBranch(), which gives pull/<id>/head for previews
and git_branch for production deployments.
Closes#9572
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
