fix(frontend): deduplicate live workflow activity

frontend/src/shell/ModelActivityPanel.tsx

@@ -5,25 +5,17 @@ import remarkGfm from "remark-gfm";
 import type { ActivityEntry, ActivityKind } from "../api/types";
 import { useSessionStore } from "../store/sessionStore";
 import { Button } from "../components/ui/button";
+import { isNearBottom } from "./activityScroll";
 
 const VISIBLE_MODEL_ACTIVITY_KINDS: ReadonlySet<ActivityKind> = new Set([
-  "prompt",
   "thinking",
   "status",
-  "gate",
 ]);
 
 export function isVisibleModelActivity(entry: ActivityEntry): boolean {
   return VISIBLE_MODEL_ACTIVITY_KINDS.has(entry.kind);
 }
 
-export function isNearBottom(
-  el: Pick<HTMLElement, "scrollHeight" | "clientHeight" | "scrollTop">,
-  threshold = 48,
-): boolean {
-  return el.scrollHeight - el.clientHeight - el.scrollTop <= threshold;
-}
-
 export function formatModelActivity(text: string): string {
   return text
     .replace(/\r\n?/g, "\n")