GitLab users see "pull request #N" wording in server text #231

Some server text still says "pull request #N" where GitLab users expect "merge request !N". Examples:

• the uncommitted-changes error in GitManager when checking out a merge request locally (apps/server/src/git/GitManager.ts);
• the merge request watch wake-up text sent to the agent.

This is upstream's wording. It's cosmetic only and isn't marked per line as a fork seam. Low priority.