After the connect fix, extension connect reached the relay but Target.getTargets
failed: 'missing field title'. The ab-connect relay builds targets from the
extension's synthesized Target.attachedToTarget; the re-announce path
(reannounceAttachedTabs) emits a minimal targetInfo {targetId,type,attached}
with no title/url, so strict deserialize of TargetInfo blew up the whole
getTargets response.
Make TargetInfo.title/url #[serde(default)] (empty) — tolerant of minimal CDP
targetInfo from the relay (and the occasional real-CDP omission). Titles
re-populate from Target.targetInfoChanged / page events after attach.