What's Changed
- docs: define runtime adapter seam contract by @Michaelyklam in #2416
- Release BE: stage-374 (v0.51.81) — 6-PR batch — cost-history POSIX lock + prompt-cache tokens + Plugins panel i18n + pending placeholder + journal partial recovery + RuntimeAdapter Slice 2 by @nesquena-hermes in #2433
Full Changelog: v0.51.80...v0.51.81