next.js

af3eefcf - Replace router-transition unit test with consolidated lifecycle e2e coverage

Replace router-transition unit test with consolidated lifecycle e2e coverage Delete the jsdom unit test; its browser-reachable scenarios move into the instrumentation-client-hook e2e suite: failure fallbacks (unparseable flight payload via middleware), server action revalidation/redirect races, and full-page (MPA) exits. The in-document defensive branches (identity-unchanged untrack, replaced-entry sweeps) have no browser-reachable trigger and are documented as accepted coverage loss. Consolidate the lifecycle describe from 28 tests to 9, one per failure mode: two journey tests cover payload shapes and route description; races, refresh and server-action interference, failure exits, and hook fault isolation each keep one focused test (the hook test now also covers a throwing start hook). Harden waits: hydration gates after full-page loads, settled event-log snapshots via waitForCommitCount instead of retry-then-refetch, and commit-filtered event picks so a stray abort fails with a readable diff.