web: remove Agent jump-to-latest button

web/src/components/agent/agent-conversation.css

@@ -238,31 +238,6 @@
   font-size:9px;
 }
 
-.agent-room__jump {
-  position:absolute;
-  z-index:2;
-  left:50%;
-  bottom:14px;
-  transform:translateX(-50%);
-  display:flex;
-  align-items:center;
-  gap:7px;
-  white-space:nowrap;
-  padding:9px 14px;
-  border:1px solid hsl(266 76% 72%/.43);
-  border-radius:99px;
-  background:hsl(256 46% 20%/.96);
-  color:hsl(263 60% 93%);
-  box-shadow:0 5px 24px hsl(240 70% 2%/.5);
-  font-size:11px;
-  cursor:pointer;
-  backdrop-filter:blur(14px);
-}
-
-.agent-room__jump:hover {
-  background:hsl(261 48% 27%);
-}
-
 .agent-room__composer-area {
   flex:none;
   border-top:1px solid hsl(253 40% 40%/.14);

web/src/components/agent/agent-conversation.tsx

@@ -1,5 +1,5 @@
 import { useEffect, useLayoutEffect, useMemo, useRef, useState } from "preact/hooks";
-import { ArrowDown, Clock3, LoaderCircle, Menu, Paperclip, X, RefreshCw, SendHorizontal, WifiOff } from "lucide-preact";
+import { Clock3, LoaderCircle, Menu, Paperclip, X, RefreshCw, SendHorizontal, WifiOff } from "lucide-preact";
 import type { Message } from "@/lib/api";
 import type { AgentRoomHookResult } from "@/hooks/use-agent-room";
 import { agentTranscriptMessages } from "@/lib/agent-room-presentation";
@@ -98,7 +98,6 @@ export function AgentConversation({ room, onOpenSidebar, isVisible = true }: Pro
   const entryAnimationsRef = useRef(new Set<Animation>());
   const typingHeightRef = useRef(0);
   const historyReadyRef = useRef(!room.isLoading);
-  const [atBottom, setAtBottom] = useState(true);
   const scrollerRef = useRef<HTMLDivElement>(null);
   const timelineRef = useRef<HTMLDivElement>(null);
   const textareaRef = useRef<HTMLTextAreaElement>(null);
@@ -151,7 +150,6 @@ export function AgentConversation({ room, onOpenSidebar, isVisible = true }: Pro
   const jumpToLatest = () => {
     pinnedRef.current = true;
     anchorRef.current = null;
-    setAtBottom(true);
     if (scrollerRef.current) {
       scrollerRef.current.scrollTop = scrollerRef.current.scrollHeight;
       restoredScrollTopRef.current = scrollerRef.current.scrollTop;
@@ -305,7 +303,6 @@ export function AgentConversation({ room, onOpenSidebar, isVisible = true }: Pro
               && Math.abs(scrollerRef.current.scrollTop - restoredScrollTopRef.current) < 1) return;
             const bottom = distanceFromBottom() <= 48;
             pinnedRef.current = bottom;
-            setAtBottom(current => current === bottom ? current : bottom);
             rememberAnchor();
             if (bottom) scheduleRead();
           }}
@@ -317,7 +314,6 @@ export function AgentConversation({ room, onOpenSidebar, isVisible = true }: Pro
             {!running && waiting && activity?.wait ? <div className="agent-room__waiting" role="status"><Clock3 size={13} /><span>Checking back at {timeFormat.format(new Date(activity.wait.due))}</span></div> : null}
           </div>
         </div>
-        {!atBottom ? <button className="agent-room__jump" onClick={jumpToLatest}><ArrowDown size={15} /><span>{room.unreadCount ? `${room.unreadCount} new message${room.unreadCount === 1 ? "" : "s"}` : "Jump to latest"}</span></button> : null}
       </div>
 
       <div className="agent-room__composer-area"