- useVirtualHistory: track last-seen ScrollBox metrics in a ref inside
the post-layout effect and bump ver when sticky/top/vp change — the
subscribe-based rearm was sufficient for fresh clicks but not for the
"hydrated mid-commit, measured empty, then metrics settle" path where
nothing re-triggered the hook until the next unrelated keystroke
- useSessionLifecycle: resume scrollToBottom from queueMicrotask to
setTimeout(..., 0) so the fresh transcript has a full task turn to
commit + measure before we try to land at the newest content
f53250b5e1