qualify_ref (ci_runs.rs:84-93) reads '#N' and an all-digit value as a PR,
anything else as a branch — so '--branch #4540' and '--branch
ops-4502-swarm-agent-icon' for the same PR/head commit answer two disjoint
questions with no indication which one was asked. Print the resolved ref
to stderr whenever --branch is given, so the output states which question
it answered.
Stdout is untouched in both plain and --json mode, so no existing
invocation's parsed output changes. An all-digit branch name stays
reachable via --branch refs/heads/<name> (already documented, unchanged).
8e6c813325