hire-an-agent now adds the new Forgejo user as a `write` collaborator on
`$FORGE_REPO` right after the token step, mirroring the collaborator setup
lib/forge-setup.sh applies to the canonical bot users. Without this, a
freshly hired agent's PATCH to assign itself an issue returned 403 Forbidden
and the dev-agent polled forever logging "claim lost to <none>".
issue_claim() now captures the PATCH HTTP status via `-w '%{http_code}'`
instead of swallowing failures with `curl -sf ... || return 1`. A 403 (or
any non-2xx) now surfaces a distinct log line naming the code — the missing
collaborator root cause would have been diagnosable in seconds instead of
minutes.
Also updates the lib-issue-claim bats mock to handle the new `-w` flag and
adds a regression test covering the HTTP-error log surfacing path.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
