Titlebar chips clipped when activating an offscreen leading tab #53412

Problem

Clicking a session tab that is scrolled out of view to the left also clips the v2 titlebar chips on the left (the Lite network badge / channel indicator). Clicking tabs already in view is fine.

Cause

titlebar.tsx calls el.scrollIntoView({ behavior: "instant" }) on tab navigation with default block: "start". That scrolls every overflow ancestor vertically as well. The titlebar row is overflow-hidden / overflow-x-auto, so its scrollTop gets pushed up and the chips are clipped.

Introduced in #30886.

Repro

1. Narrow window, open enough session tabs that the strip overflows horizontally.
2. Activate a trailing tab so the leading tabs are offscreen.
3. Click a leading tab.

Expected: only horizontal scroll. Actual: the titlebar content is also scrolled vertically and chips are cut off.

Fix

Pass block: "nearest", inline: "nearest" (and optionally overflow-y-hidden on the horizontal strip) so only the necessary axis scrolls.