v3.20.0

What's Changed

• fix(amazon): start review lane at search time so multi-source runs keep a real budget by @mvanhorn in #999
• fix(grok): treat expired sessions as degraded, not ok by @mvanhorn in #1000
• feat(x): retrieve-judge-retry so X stays on-topic by @mvanhorn in #998
• chore(release): bump version to 3.20.0 by @mvanhorn in #1003

Full Changelog: v3.19.0...v3.20.0