Previously when the access-hook returned non-zero, git-http would pipe
the hook's stderr into the 403 body sent back to the agent's git
client but never log it locally, so docker logs just showed
`"GET ... 403 -"` with no explanation. Operators had to shell into
the sidecar and re-run the hook by hand to find out why a clone was
being refused (e.g. upstream SSH unreachable, missing credentials).
Route the hook's stderr/stdout through the existing log_message
channel before sending the 403, one log line per output line so the
default request-log format stays readable. When the hook exits
non-zero with no output, log the exit code so the line is still
informative.
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
didericis