fix(frontend): deduplicate live workflow activity

frontend/src/shell/AppShell.new-session.test.tsx

@@ -1,4 +1,4 @@
-import { render, screen, waitFor, within } from "@testing-library/react";
+import { act, render, screen, waitFor, within } from "@testing-library/react";
 import userEvent from "@testing-library/user-event";
 import { http, HttpResponse, delay } from "msw";
 import { QueryClient, QueryClientProvider } from "@tanstack/react-query";
@@ -45,7 +45,7 @@ test("New session starts prewarm without delaying composer focus", async () => {
   expect(composer).toHaveClass("thot-awaiting-input");
 });
 
-test("shows the question and creation timer before POST /sessions resolves, then opens SSE", async () => {
+test("records the prompt without central duplication, then opens the live log", async () => {
   let releaseCreate!: () => void;
   const createMayFinish = new Promise<void>((resolve) => { releaseCreate = resolve; });
   server.use(
@@ -60,20 +60,20 @@ test("shows the question and creation timer before POST /sessions resolves, then
   await userEvent.type(composer, "How many patients?");
   await userEvent.click(screen.getByRole("button", { name: /send/i }));
 
-  expect(await screen.findByText("How many patients?", { selector: "p" })).toBeInTheDocument();
-  expect(screen.getByText("Creating session…")).toBeInTheDocument();
-  expect(screen.getByText(/\d+s/)).toBeInTheDocument();
+  expect(screen.queryByText("How many patients?", { selector: "p" })).not.toBeInTheDocument();
+  expect(screen.queryByText("Creating session…")).not.toBeInTheDocument();
+  expect(screen.queryByText(/\d+s/)).not.toBeInTheDocument();
   expect(useSessionStore.getState().activityLog[0]).toEqual({
     kind: "prompt",
     phase: "F1",
     text: "How many patients?",
   });
-  expect(FakeEventSource.instances).toHaveLength(0);
-
   releaseCreate();
   await waitFor(() => expect(FakeEventSource.instances).toHaveLength(1));
-  expect(screen.getByText("How many patients?", { selector: "p" })).toBeInTheDocument();
-  expect(screen.getByText("Analyzing question…")).toBeInTheDocument();
+  act(() => FakeEventSource.instances[0].emit({ type: "text_delta", text: "Inspecting cohort" }));
+  expect(await screen.findByRole("log", { name: "Live model activity" }))
+    .toHaveTextContent("Inspecting cohort");
+  expect(screen.queryByText("Analyzing question…")).not.toBeInTheDocument();
   expect(useSessionStore.getState().currentPhase).toBe("F1");
 });
 

frontend/src/shell/AppShell.session-mgmt.test.tsx

@@ -697,15 +697,13 @@ test("closing and reopening Model activity preserves the complete activity log",
     const store = useSessionStore.getState();
     store.setPhase("F4");
     store.setLastUserEntry({ kind: "input", text: "Inspect patient cohort" });
-    store.applyEvent({
-      type: "activity_event",
-      activity: { kind: "tool", toolCallId: "tool-1", toolName: "bash", status: "running" },
-    });
     store.applyEvent({
       type: "activity_event",
       activity: { kind: "tool", toolCallId: "tool-1", toolName: "bash", status: "completed" },
     });
     store.applyEvent({ type: "text_delta", text: "Cohort ready" });
+    store.applyEvent({ type: "activity_delta", text: "Inspecting **cohort**" });
+    store.applyEvent({ type: "info", level: "info", text: "Cohort status" });
   });
   const beforeClose = useSessionStore.getState().activityLog.map((entry) => ({ ...entry }));
 
@@ -713,7 +711,9 @@ test("closing and reopening Model activity preserves the complete activity log",
   await userEvent.click(screen.getByRole("button", { name: /model activity/i }));
   const panel = (await screen.findByRole("heading", { name: /model activity/i })).closest("aside");
   expect(panel).not.toBeNull();
-  expect(within(panel!).getByText("Inspect patient cohort")).toBeInTheDocument();
+  expect(within(panel!).getByText("cohort").tagName).toBe("STRONG");
+  expect(within(panel!).getByText("Cohort status")).toBeInTheDocument();
+  expect(within(panel!).queryByText("Inspect patient cohort")).not.toBeInTheDocument();
   expect(within(panel!).queryByText("bash")).not.toBeInTheDocument();
   expect(within(panel!).queryByText("Cohort ready")).not.toBeInTheDocument();
 
@@ -724,7 +724,9 @@ test("closing and reopening Model activity preserves the complete activity log",
   await userEvent.click(screen.getByRole("button", { name: /show model activity/i }));
   const reopened = (await screen.findByRole("heading", { name: /model activity/i })).closest("aside");
   expect(reopened).not.toBeNull();
-  expect(within(reopened!).getByText("Inspect patient cohort")).toBeInTheDocument();
+  expect(within(reopened!).getByText("cohort").tagName).toBe("STRONG");
+  expect(within(reopened!).getByText("Cohort status")).toBeInTheDocument();
+  expect(within(reopened!).queryByText("Inspect patient cohort")).not.toBeInTheDocument();
   expect(within(reopened!).queryByText("bash")).not.toBeInTheDocument();
   expect(within(reopened!).queryByText("Cohort ready")).not.toBeInTheDocument();
   expect(useSessionStore.getState().activityLog).toEqual(beforeClose);

frontend/src/shell/AppShell.tsx

@@ -279,7 +279,7 @@ export function AppShell() {
   // The harness "holds the ball" whenever a session is live, no widget is waiting on
   // the human, AND the Pi turn is still in flight (agentActive). Without the last
   // condition the final workflow step — which ends with no follow-up gate — would
-  // leave the spinner on forever.
+  // leave the working state on forever.
   const pendingWidget = useSessionStore((s) => s.pendingWidget);
   const resetSession = useSessionStore((s) => s.resetSession);
   const recordLifecycle = useSessionStore((s) => s.recordLifecycle);
@@ -289,7 +289,7 @@ export function AppShell() {
   const agentActive = useSessionStore((s) => s.agentActive);
   const sessionViewOpen = Boolean(activeSessionId) || creatingSession;
   const working = sessionViewOpen && !pendingWidget && agentActive;
-  // Processing time counts only while the harness works, not while a finalized
+  // The workflow bar runs only while the harness works, not while a finalized
   // session sits idle or a gate awaits the reviewer (pendingWidget).
   const running = working && !finalized;
 
@@ -336,7 +336,7 @@ export function AppShell() {
   }
 
   function finishSessionCreation(id: string) {
-    // React batches these updates, preserving the provisional view and timer
+    // React batches these updates, preserving the provisional session view
     // while useSessionStream opens the durable session's SSE channel.
     selectActiveSession(id);
     setCreatingSession(false);
@@ -406,10 +406,7 @@ export function AppShell() {
           <div className="mx-auto flex max-w-4xl flex-col gap-6">
             {sessionViewOpen ? (
               <>
-                <CentralStatus
-                  working={working}
-                  workingLabel={creatingSession ? "Creating session…" : "Analyzing question…"}
-                />
+                <CentralStatus working={working} />
                 {activeSessionId && <WidgetHost sessionId={activeSessionId} />}
                 {finalized && !agentActive && (
                   <div className="rounded-2xl border border-border/80 bg-card p-5 text-center shadow-md">

frontend/src/shell/CentralStatus.test.tsx

@@ -1,43 +1,85 @@
-import { render, screen } from "@testing-library/react";
+import { act, fireEvent, render, screen } from "@testing-library/react";
 import { beforeEach } from "vitest";
 import { useSessionStore } from "../store/sessionStore";
 import { CentralStatus } from "./CentralStatus";
 
 beforeEach(() => useSessionStore.getState().resetSession());
 
-test("the working spinner is a pure status indicator (no activity toggle on it)", () => {
-  useSessionStore.getState().applyEvent({ type: "text_delta", text: "reading the schema" });
+function setScrollGeometry(
+  element: HTMLElement,
+  values: { scrollHeight: number; clientHeight: number; scrollTop: number },
+) {
+  Object.defineProperties(element, {
+    scrollHeight: { configurable: true, value: values.scrollHeight },
+    clientHeight: { configurable: true, value: values.clientHeight },
+    scrollTop: { configurable: true, writable: true, value: values.scrollTop },
+  });
+}
+
+test("renders only the chronological assistant transcript log while working", () => {
+  useSessionStore.setState({
+    lastUserEntry: { kind: "input", text: "how many patients?" },
+    stepMessages: [{ level: "warning", text: "Searching the schema…" }],
+    transcript: [
+      { role: "assistant", text: "First line\n\nSecond line" },
+      { role: "assistant", text: "Third line" },
+    ],
+  });
+
   render(<CentralStatus working />);
-  // The spinner no longer opens the panel — that moved to the header arrow toggle.
-  expect(screen.queryByRole("button", { name: /model activity/i })).not.toBeInTheDocument();
-  expect(screen.getByRole("status")).toBeInTheDocument();
+
+  const log = screen.getByRole("log", { name: "Live model activity" });
+  expect(log).toHaveTextContent("First line");
+  expect(log).toHaveTextContent("Second line");
+  expect(log).toHaveTextContent("Third line");
+  expect(log).toHaveClass("max-h-28", "overflow-y-auto");
+  expect(screen.queryByText("how many patients?")).not.toBeInTheDocument();
+  expect(screen.queryByText("Searching the schema…")).not.toBeInTheDocument();
+  expect(screen.queryByRole("status")).not.toBeInTheDocument();
+  expect(screen.queryByText(/\d+s/)).not.toBeInTheDocument();
 });
 
-test("renders nothing when not working and there is no user entry or step messages", () => {
-  const { container } = render(<CentralStatus working={false} />);
+test("wraps live log lines instead of truncating them", () => {
+  useSessionStore.setState({
+    transcript: [{ role: "assistant", text: "a_very_long_model_activity_line" }],
+  });
+  render(<CentralStatus working />);
+  expect(screen.getByText("a_very_long_model_activity_line")).toHaveClass(
+    "whitespace-pre-wrap",
+    "break-words",
+  );
+  expect(screen.getByText("a_very_long_model_activity_line")).not.toHaveClass("truncate");
+});
+
+test.each([
+  { working: false, transcript: [{ role: "assistant" as const, text: "hidden" }] },
+  { working: true, transcript: [] },
+  { working: true, transcript: [{ role: "assistant" as const, text: " \n " }] },
+])("renders nothing without active non-blank transcript content", ({ working, transcript }) => {
+  useSessionStore.setState({ transcript });
+  const { container } = render(<CentralStatus working={working} />);
   expect(container).toBeEmptyDOMElement();
 });
 
-test("echoes the last user entry and the step messages", () => {
-  const st = useSessionStore.getState();
-  st.setLastUserEntry({ kind: "input", text: "how many patients?" });
-  st.applyEvent({ type: "info", level: "info", text: "Searching the schema…" });
-  render(<CentralStatus working={false} />);
-  expect(screen.getByText("how many patients?")).toBeInTheDocument();
-  expect(screen.getByText("Searching the schema…")).toBeInTheDocument();
-});
-
-test("shows a working indicator with elapsed time and the model-stream tail while working", () => {
-  useSessionStore.getState().applyEvent({ type: "text_delta", text: "Reading the schema for dim_patient" });
+test("bottom-follows appended transcript text only while near the bottom", () => {
+  useSessionStore.setState({ transcript: [{ role: "assistant", text: "First" }] });
   render(<CentralStatus working />);
-  // elapsed time (e.g. "0s")
-  expect(screen.getByText(/\d+s/)).toBeInTheDocument();
-  // a short tail of the model's current output
-  expect(screen.getByText(/Reading the schema for dim_patient/)).toBeInTheDocument();
+  const log = screen.getByRole("log", { name: "Live model activity" });
+  setScrollGeometry(log, { scrollHeight: 400, clientHeight: 100, scrollTop: 300 });
+
+  act(() => useSessionStore.getState().applyEvent({ type: "text_delta", text: " second" }));
+
+  expect(log.scrollTop).toBe(400);
 });
 
-test("no working indicator when not working, even with a transcript", () => {
-  useSessionStore.getState().applyEvent({ type: "text_delta", text: "background narration" });
-  render(<CentralStatus working={false} />);
-  expect(screen.queryByText(/\d+s/)).not.toBeInTheDocument();
+test("preserves manual live-log scroll position away from the bottom", () => {
+  useSessionStore.setState({ transcript: [{ role: "assistant", text: "First" }] });
+  render(<CentralStatus working />);
+  const log = screen.getByRole("log", { name: "Live model activity" });
+  setScrollGeometry(log, { scrollHeight: 400, clientHeight: 100, scrollTop: 100 });
+  fireEvent.scroll(log);
+
+  act(() => useSessionStore.getState().applyEvent({ type: "text_delta", text: " second" }));
+
+  expect(log.scrollTop).toBe(100);
 });

frontend/src/shell/CentralStatus.tsx

@@ -1,76 +1,50 @@
-import { useEffect, useReducer, useState } from "react";
+import { useLayoutEffect, useRef } from "react";
 import { useSessionStore } from "../store/sessionStore";
-import { WorkingSpinner } from "./WorkingSpinner";
+import { isNearBottom } from "./activityScroll";
 
-/** Last few non-blank lines of a string — a compact "what the model is doing now"
- *  tail (mirrors ModelActivityPanel's tail-line logic, at a smaller size). Returned
- *  as an array so each line renders as its own formatted log row. */
-function tailLines(s: string, n = 5): string[] {
-  return s
+function transcriptLines(transcript: Array<{ text: string }>): string[] {
+  return transcript.flatMap(({ text }) =>
+    text
       .split("\n")
-    .map((l) => l.trimEnd())
-    .filter((l) => l.trim() !== "")
-    .slice(-n);
+      .map((line) => line.trimEnd())
+      .filter((line) => line.trim() !== ""),
+  );
 }
 
-/** The minimal central view: the user's last input/choice, a live "working" indicator
- *  (elapsed time + a short tail of the model stream) while the model is busy, and the
- *  gate's curated messages for the current step. The full verbose stream lives in the
- *  left Model-activity panel. */
-export function CentralStatus({ working, workingLabel }: { working: boolean; workingLabel?: string }) {
-  const lastUserEntry = useSessionStore((s) => s.lastUserEntry);
-  const stepMessages = useSessionStore((s) => s.stepMessages);
-  const transcript = useSessionStore((s) => s.transcript);
+/** Compact central projection of the assistant stream while the model is working. */
+export function CentralStatus({ working }: { working: boolean }) {
+  const transcript = useSessionStore((state) => state.transcript);
+  const rows = transcriptLines(transcript);
+  const rowCount = rows.length;
+  const tail = rows.at(-1);
+  const scrollRef = useRef<HTMLOListElement>(null);
+  const followRef = useRef(true);
 
-  const [startedAt, setStartedAt] = useState<number | null>(null);
-  const [, tick] = useReducer((x: number) => x + 1, 0);
+  useLayoutEffect(() => {
+    const viewport = scrollRef.current;
+    if (viewport && followRef.current) viewport.scrollTop = viewport.scrollHeight;
+  }, [rowCount, tail]);
 
-  // Start the per-step timer when work begins; tick once a second so the elapsed
-  // display updates; clear it when work stops.
-  useEffect(() => {
-    if (!working) {
-      setStartedAt(null);
-      return;
-    }
-    setStartedAt((prev) => prev ?? Date.now());
-    const id = setInterval(tick, 1000);
-    return () => clearInterval(id);
-  }, [working]);
-
-  if (!working && !lastUserEntry && stepMessages.length === 0) return null;
-
-  const elapsed = startedAt ? Math.max(0, Math.floor((Date.now() - startedAt) / 1000)) : 0;
-  const tailRows = tailLines(transcript.at(-1)?.text ?? "");
+  if (!working || rows.length === 0) return null;
 
   return (
-    <div className="flex flex-col gap-3">
-      {lastUserEntry && (
-        <div className="rounded-lg border border-border/70 bg-card px-3 py-2">
-          <span className="thot-label">
-            {lastUserEntry.kind === "input" ? "You asked" : "You chose"}
-          </span>
-          <p className="mt-0.5 text-sm text-foreground">{lastUserEntry.text}</p>
-        </div>
-      )}
-
-      {working && (
-        <div className="flex flex-col gap-1.5">
-          <div className="flex min-w-0 items-center gap-2 text-sm text-muted-foreground">
-            {/* Pure status indicator — opening the activity panel now lives on the
-                dedicated arrow toggle in the header, not on this spinner. */}
-            <span className="grid size-5 shrink-0 place-items-center text-primary">
-              <WorkingSpinner spinning className="size-3.5" />
-            </span>
-            <span className="shrink-0 font-mono tabular-nums">{elapsed}s</span>
-            <span>{workingLabel ?? "ThothII is working"}</span>
-          </div>
-          {tailRows.length > 0 && (
-            <ol className="ml-7 flex flex-col gap-0.5 overflow-hidden rounded-lg border border-border/60 bg-muted/40 px-3 py-2">
-              {tailRows.map((line, i) => {
-                const isLast = i === tailRows.length - 1;
+    <ol
+      ref={scrollRef}
+      role="log"
+      aria-label="Live model activity"
+      aria-live="polite"
+      aria-relevant="additions text"
+      tabIndex={0}
+      className="max-h-28 overflow-y-auto rounded-lg border border-border/60 bg-muted/40 px-3 py-2 outline-none focus-visible:ring-2 focus-visible:ring-inset focus-visible:ring-ring/40"
+      onScroll={(event) => {
+        followRef.current = isNearBottom(event.currentTarget);
+      }}
+    >
+      {rows.map((line, index) => {
+        const isLast = index === rows.length - 1;
         return (
           <li
-                    key={i}
+            key={index}
             className={[
               "flex items-baseline gap-2 font-mono text-[0.72rem] leading-relaxed",
               isLast ? "text-foreground/80" : "text-muted-foreground/55",
@@ -78,35 +52,14 @@ export function CentralStatus({ working, workingLabel }: { working: boolean; wor
           >
             <span
               aria-hidden
-                      className={[
-                        "shrink-0 select-none",
-                        isLast ? "text-primary" : "text-muted-foreground/35",
-                      ].join(" ")}
+              className={isLast ? "shrink-0 select-none text-primary" : "shrink-0 select-none text-muted-foreground/35"}
             >
               ›
             </span>
-                    <span className="min-w-0 flex-1 truncate">{line}</span>
+            <span className="min-w-0 flex-1 whitespace-pre-wrap break-words">{line}</span>
           </li>
         );
       })}
     </ol>
-          )}
-        </div>
-      )}
-
-      {stepMessages.map((m, i) => (
-        <p
-          key={i}
-          className={[
-            "text-sm",
-            m.level === "error" ? "text-destructive"
-              : m.level === "warning" ? "text-amber-600"
-              : "text-foreground/90",
-          ].join(" ")}
-        >
-          {m.text}
-        </p>
-      ))}
-    </div>
   );
 }

frontend/src/shell/ModelActivityPanel.test.tsx

@@ -3,12 +3,13 @@ import userEvent from "@testing-library/user-event";
 import { beforeEach, vi } from "vitest";
 import type { ActivityEntry, ActivityKind } from "../api/types";
 import { useSessionStore } from "../store/sessionStore";
+import { isNearBottom } from "./activityScroll";
 import * as activityPanelModule from "./ModelActivityPanel";
-import { isNearBottom, ModelActivityPanel } from "./ModelActivityPanel";
+import { ModelActivityPanel } from "./ModelActivityPanel";
 
 beforeEach(() => useSessionStore.getState().resetSession());
 
-test("renders only prompt, thinking, status, and gate from a mixed F1 sequence", () => {
+test("renders only thinking and status from a mixed F1 sequence", () => {
   const store = useSessionStore.getState();
   store.setPhase("F1");
   store.setLastUserEntry({ kind: "input", text: "How many patients?" });
@@ -17,10 +18,6 @@ test("renders only prompt, thinking, status, and gate from a mixed F1 sequence",
     type: "activity_event",
     activity: { kind: "tool", toolCallId: "tool-1", toolName: "bash", status: "running" },
   });
-  store.applyEvent({
-    type: "activity_event",
-    activity: { kind: "tool", toolCallId: "tool-1", toolName: "bash", status: "completed" },
-  });
   store.applyEvent({ type: "text_delta", text: "Let me run another bash search." });
   store.applyEvent({ type: "activity_delta", text: "Inspecting **schema**." });
   store.applyEvent({ type: "info", level: "warning", text: "Retrying schema lookup" });
@@ -31,14 +28,12 @@ test("renders only prompt, thinking, status, and gate from a mixed F1 sequence",
 
   render(<ModelActivityPanel onClose={vi.fn()} />);
 
-  expect(screen.getAllByRole("article")).toHaveLength(4);
-  expect(screen.getByText("How many patients?")).toBeInTheDocument();
+  expect(screen.getAllByRole("article")).toHaveLength(2);
   expect(screen.getByText("schema").tagName).toBe("STRONG");
   expect(screen.getByText("Retrying schema lookup")).toBeInTheDocument();
-  expect(screen.getByText("Confirm cohort")).toBeInTheDocument();
-  expect(screen.queryByText("Agent started")).not.toBeInTheDocument();
+  expect(screen.queryByText("How many patients?")).not.toBeInTheDocument();
+  expect(screen.queryByText("Confirm cohort")).not.toBeInTheDocument();
   expect(screen.queryByText("bash")).not.toBeInTheDocument();
-  expect(screen.queryByText("completed")).not.toBeInTheDocument();
   expect(screen.queryByText("Let me run another bash search.")).not.toBeInTheDocument();
   expect(useSessionStore.getState().transcript).toEqual([
     { role: "assistant", text: "Let me run another bash search." },
@@ -52,10 +47,10 @@ test("uses an explicit default-deny activity-kind allowlist", () => {
   expect(predicate).toBeTypeOf("function");
   if (!predicate) return;
 
-  for (const kind of ["prompt", "thinking", "status", "gate"] satisfies ActivityKind[]) {
+  for (const kind of ["thinking", "status"] satisfies ActivityKind[]) {
     expect(predicate({ kind, phase: "F1", text: kind })).toBe(true);
   }
-  for (const kind of ["assistant", "tool", "lifecycle"] satisfies ActivityKind[]) {
+  for (const kind of ["prompt", "gate", "assistant", "tool", "lifecycle"] satisfies ActivityKind[]) {
     expect(predicate({ kind, phase: "F1", text: kind })).toBe(false);
   }
   expect(predicate({ kind: "future-kind" as ActivityKind, phase: "F1", text: "future" })).toBe(false);
@@ -64,6 +59,8 @@ test("uses an explicit default-deny activity-kind allowlist", () => {
 test("shows the empty state when the raw log contains only hidden entries", () => {
   useSessionStore.setState({
     activityLog: [
+      { kind: "prompt", phase: "F1", text: "How many patients?" },
+      { kind: "gate", phase: "F1", text: "Confirm cohort" },
       { kind: "assistant", phase: "F1", text: "Let me try another command." },
       { kind: "tool", phase: "F1", text: "bash", toolCallId: "tool-1", status: "completed" },
       { kind: "lifecycle", phase: "F1", text: "Turn end" },
@@ -122,7 +119,7 @@ test("renders thinking markdown without assistant narration", () => {
 test("close calls onClose without mutating the activity log", async () => {
   const onClose = vi.fn();
   const activityLog: ActivityEntry[] = [
-    { kind: "prompt", phase: "F1", text: "Keep this row" },
+    { kind: "status", phase: "F1", text: "Keep this row" },
   ];
   useSessionStore.setState({ activityLog });
   render(<ModelActivityPanel onClose={onClose} />);
@@ -151,9 +148,9 @@ function setScrollGeometry(
   });
 }
 
-test("follows appended activity while the viewport is near the bottom", () => {
+test("follows appended visible activity while near the bottom", () => {
   useSessionStore.setState({
-    activityLog: [{ kind: "prompt", phase: "F1", text: "First" }],
+    activityLog: [{ kind: "thinking", phase: "F1", text: "First" }],
   });
   render(<ModelActivityPanel onClose={vi.fn()} />);
   const viewport = screen.getByTestId("activity-scroll");
@@ -165,9 +162,9 @@ test("follows appended activity while the viewport is near the bottom", () => {
   expect(viewport).toHaveAttribute("tabindex", "0");
 });
 
-test("preserves manual scroll position when appended activity arrives", () => {
+test("preserves manual scroll position when visible activity arrives", () => {
   useSessionStore.setState({
-    activityLog: [{ kind: "prompt", phase: "F1", text: "First" }],
+    activityLog: [{ kind: "thinking", phase: "F1", text: "First" }],
   });
   render(<ModelActivityPanel onClose={vi.fn()} />);
   const viewport = screen.getByTestId("activity-scroll");
@@ -179,18 +176,15 @@ test("preserves manual scroll position when appended activity arrives", () => {
   expect(viewport.scrollTop).toBe(100);
 });
 
-test("does not bottom-follow when only a hidden event arrives", () => {
+test("does not bottom-follow when only a hidden prompt arrives", () => {
   useSessionStore.setState({
-    activityLog: [{ kind: "prompt", phase: "F1", text: "Visible prompt" }],
+    activityLog: [{ kind: "status", phase: "F1", text: "Visible status" }],
   });
   render(<ModelActivityPanel onClose={vi.fn()} />);
   const viewport = screen.getByTestId("activity-scroll");
   setScrollGeometry(viewport, { scrollHeight: 400, clientHeight: 100, scrollTop: 300 });
 
-  act(() => useSessionStore.getState().applyEvent({
-    type: "activity_event",
-    activity: { kind: "tool", toolCallId: "tool-2", toolName: "bash", status: "running" },
-  }));
+  act(() => useSessionStore.getState().setLastUserEntry({ kind: "input", text: "Hidden prompt" }));
 
   expect(viewport.scrollTop).toBe(300);
 });

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")

frontend/src/shell/activityScroll.ts

@@ -0,0 +1,6 @@
+export function isNearBottom(
+  el: Pick<HTMLElement, "scrollHeight" | "clientHeight" | "scrollTop">,
+  threshold = 48,
+): boolean {
+  return el.scrollHeight - el.clientHeight - el.scrollTop <= threshold;
+}