request-session retries preflight on catalog errors

skillsv0.9.12026-05-19

What changed

request-session previously treated any non-200 response from the catalog preflight as a hard failure, which meant transient catalog blips would abort otherwise-valid session approvals. The skill now retries 503 and timeout responses up to three times with exponential backoff before propagating the error.

Approval cancellations attributable to catalog flakiness should drop noticeably. Permanent errors (404 service-not-found, 403 unauthorized) are still surfaced immediately so agents don't waste time retrying.

Included changes:

• feat(request-session): retry preflight on 503/timeout
• docs(request-session): document the retry behavior in SKILL.md