Core Changes
- chore: warn when running tests against stale build: #88001
- Redesign default error pages with cleaner, more user-friendly UI: #87988
- dx: avoid next-env.d.ts change in dev: #88103
- prevent browser cache from using stale RSC responses from previous builds: #86554
Misc Changes
- chore: add Claude Code configuration: #87943
- test: reduce flakiness in opentelemetry test for prod mode: #88102
- Rename CLAUDE.md to AGENTS.md with symlink: #88105
Credits
Huge thanks to @feedthejim, @huozhi, and @ztanner for helping!