web: holding PageUp/PageDown scrolls at a crawl

Description

Holding PageUp/PageDown in the V2 web UI scrolls very slowly. A single press pages normally; holding the key barely moves the viewport. ArrowUp/ArrowDown have the same problem.

Cause: packages/ui/src/components/scroll-view.tsx handles scroll keys with viewportRef.scrollBy({ top: ±amount, behavior: "smooth" }) on every keydown. OS auto-repeat re-fires every ~30–50ms, and each smooth scrollBy aborts the in-flight smooth animation and restarts it from the current offset, so the viewport only advances the first slow ease-in frames.

Fix: use behavior: "auto" for keyboard paging, or accumulate a pending target and update the smooth destination instead of restarting the animation per repeat.

Plugins

None

OpenCode version

2.0.8

Steps to reproduce

1. Open a session with more than one screen of messages in the V2 web UI.
2. Press and hold PageUp.

Observed: crawls upward. Expected: continuous page-per-repeat. Tapping PageUp repeatedly pages correctly.

Screenshot and/or share link

n/a

Operating System

Windows 11 (WSL2; Linux 6.18 x86_64)

Terminal

n/a (web UI, Chromium)

Start in packages/ui/src/components/scroll-view.tsx and inspect the keyboard scroll handler using viewportRef.scrollBy. Reproduce the issue in the V2 web UI by holding PageUp, PageDown, or an arrow key, then verify that repeated key events produce continuous page-sized movement without restarting smooth scrolling.