feat(desktop): marquee clipped inline row titles on hover

The one-line session row gets the exact treatment the inbox card's title
already has: hovering a truncated title glides the clipped tail into view —
one direction at constant speed, a short hold at each end, then a snap back.
Same armMarquee/disarmMarquee handlers, same CSS, so overflow is measured on
pointerenter, short titles never move, hover state lives in DOM attributes
(no re-render of the memoized row), and reduced motion disables it.

apps/desktop/src/app/chat/sidebar/session-row.tsx

@@ -438,8 +438,12 @@ function SidebarSessionRowImpl({
                 <>
                   {leadNode}
                   {handoffBadge}
-                  <SidebarRowLabel className="flex-1 font-normal group-hover:text-foreground group-data-[working=true]:text-foreground/90">
-                    {title}
+                  <SidebarRowLabel
+                    className="hover-marquee flex-1 font-normal group-hover:text-foreground group-data-[working=true]:text-foreground/90"
+                    onPointerEnter={armMarquee}
+                    onPointerLeave={disarmMarquee}
+                  >
+                    <span className="hover-marquee-inner">{title}</span>
                   </SidebarRowLabel>
                 </>
               )