fix(desktop): keep quiet sessions visibly running

apps/desktop/src/app/chat/sidebar/session-row-state.test.ts

@@ -0,0 +1,43 @@
+import { describe, expect, it } from 'vitest'
+
+import { sessionDotState, sessionShowsRunningArc } from './session-row-state'
+
+describe('session row running appearance', () => {
+  it('keeps the running arc when an authoritative turn becomes quiet', () => {
+    expect(sessionShowsRunningArc({ isWorking: true, needsInput: false })).toBe(true)
+    expect(
+      sessionDotState({
+        hasBackground: false,
+        isStalled: true,
+        isUnread: false,
+        isWorking: true,
+        needsInput: false
+      })
+    ).toBe('stalled')
+  })
+
+  it('uses the needs-input treatment instead of the running arc', () => {
+    expect(sessionShowsRunningArc({ isWorking: true, needsInput: true })).toBe(false)
+    expect(
+      sessionDotState({
+        hasBackground: true,
+        isStalled: true,
+        isUnread: true,
+        isWorking: true,
+        needsInput: true
+      })
+    ).toBe('needs-input')
+  })
+
+  it('keeps background and unread states below active-turn states', () => {
+    expect(
+      sessionDotState({
+        hasBackground: true,
+        isStalled: false,
+        isUnread: true,
+        isWorking: false,
+        needsInput: false
+      })
+    ).toBe('background')
+  })
+})

apps/desktop/src/app/chat/sidebar/session-row-state.ts

@@ -0,0 +1,42 @@
+export type SessionDotState = 'background' | 'idle' | 'needs-input' | 'stalled' | 'unread' | 'working'
+
+interface SessionRowState {
+  hasBackground: boolean
+  isStalled: boolean
+  isUnread: boolean
+  isWorking: boolean
+  needsInput: boolean
+}
+
+/** Resolve the sidebar dot's mutually-exclusive display state by priority. */
+export function sessionDotState({
+  hasBackground,
+  isStalled,
+  isUnread,
+  isWorking,
+  needsInput
+}: SessionRowState): SessionDotState {
+  if (needsInput) {
+    return 'needs-input'
+  }
+
+  if (isWorking) {
+    return isStalled ? 'stalled' : 'working'
+  }
+
+  if (hasBackground) {
+    return 'background'
+  }
+
+  return isUnread ? 'unread' : 'idle'
+}
+
+/** A quiet turn is still authoritatively running. Keep the unmistakable row
+ * arc until the gateway reports completion; only a blocking prompt suppresses
+ * it in favour of the needs-input treatment. */
+export function sessionShowsRunningArc({
+  isWorking,
+  needsInput
+}: Pick<SessionRowState, 'isWorking' | 'needsInput'>): boolean {
+  return isWorking && !needsInput
+}

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

@@ -17,11 +17,12 @@ import { cn } from '@/lib/utils'
 import { $backgroundRunningSessionIds } from '@/store/composer-status'
 import { $unreadFinishedSessionIds } from '@/store/session'
 import { $sessionColorById } from '@/store/session-color'
-import { $attentionSessionIds, openSessionTile } from '@/store/session-states'
+import { $attentionSessionIds, $stalledSessionIds, openSessionTile } from '@/store/session-states'
 import { canOpenSessionWindow, openSessionInNewWindow } from '@/store/windows'
 
 import { SidebarRowBody, SidebarRowGrab, SidebarRowLabel, SidebarRowLead, SidebarRowShell } from './chrome'
 import { SessionActionsMenu, SessionContextMenu } from './session-actions-menu'
+import { type SessionDotState, sessionDotState, sessionShowsRunningArc } from './session-row-state'
 import { useProfilePrewarm } from './use-profile-prewarm'
 
 interface SidebarSessionRowProps extends React.ComponentProps<'div'> {
@@ -90,6 +91,9 @@ export function SidebarSessionRow({
   // True when the session's most recent turn finished in the background (while
   // the user was viewing a different session) and hasn't been opened since.
   const isUnread = useStore($unreadFinishedSessionIds).includes(session.id)
+  // True when the turn is still running but the stream has been quiet long
+  // enough to soften the animation. This must never look like an idle row.
+  const isStalled = useStore($stalledSessionIds).includes(session.id)
   // True when a terminal(background=true) process is alive in this session.
   const hasBackground = useStore($backgroundRunningSessionIds).includes(session.id)
   // The session's resolved color (idle dot tint), read from the ONE shared map
@@ -99,15 +103,7 @@ export function SidebarSessionRow({
   // Resolve the dot's display state once — the four signals are mutually
   // exclusive by priority, so threading them as booleans through wrappers just
   // to collapse them at the leaf is backwards.
-  const dotState: SessionDotState = needsInput
-    ? 'needs-input'
-    : isWorking
-      ? 'working'
-      : hasBackground
-        ? 'background'
-        : isUnread
-          ? 'unread'
-          : 'idle'
+  const dotState = sessionDotState({ hasBackground, isStalled, isUnread, isWorking, needsInput })
 
   return (
     <SessionContextMenu
@@ -183,7 +179,7 @@ export function SidebarSessionRow({
         style={style}
         {...rest}
       >
-        {isWorking && !needsInput && <span aria-hidden="true" className="arc-border" />}
+        {sessionShowsRunningArc({ isWorking, needsInput }) && <span aria-hidden="true" className="arc-border" />}
         <SidebarRowBody
           className={cn('z-0 group-hover:pr-12', branchStem && 'pl-3.5')}
           // Middle-click = open in a new tab (browser muscle memory). Swallow
@@ -271,11 +267,6 @@ export function SidebarSessionRow({
   )
 }
 
-/** The session's display state for the sidebar lead dot. The call site
- *  resolves this from the four underlying signals (needs-input, working,
- *  background, unread) so the dot component itself is a pure lookup. */
-type SessionDotState = 'background' | 'idle' | 'needs-input' | 'unread' | 'working'
-
 function SessionRowLeadDot({
   branchStem,
   dotState = 'idle',
@@ -333,6 +324,14 @@ const DOT_VARIANTS: Record<SessionDotState, DotVariant> = {
     className: `${DOT_BASE} bg-(--ui-accent) shadow-[0_0_0.625rem_color-mix(in_srgb,var(--ui-accent)_55%,transparent)] ${PING} before:bg-(--ui-accent) before:opacity-70`,
     role: 'status'
   },
+  // Quiet accent pulse — the turn is still authoritative-running, but no
+  // stream activity has arrived for the watchdog window.
+  stalled: {
+    ariaLabel: r => r.sessionRunning,
+    className: `${DOT_BASE} bg-(--ui-accent) opacity-70 ${PING} before:bg-(--ui-accent) before:opacity-40`,
+    role: 'status',
+    title: r => r.sessionRunning
+  },
   // Pulsing gray — a terminal(background=true) process is alive while the LLM
   // is idle. Gray (not accent) reads as "something chugging along". Brighter
   // than muted-foreground so it's visible against the sidebar surface.

apps/desktop/src/app/contrib/hooks/use-background-sync.test.ts

@@ -0,0 +1,75 @@
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+
+import {
+  $attentionSessionIds,
+  $stalledSessionIds,
+  $workingSessionIds,
+  clearAllSessionStates,
+  SESSION_WATCHDOG_TIMEOUT_MS
+} from '@/store/session-states'
+
+import { rehydrateLiveSessionStatuses } from './use-background-sync'
+
+describe('rehydrateLiveSessionStatuses', () => {
+  beforeEach(() => {
+    vi.useFakeTimers()
+  })
+
+  afterEach(() => {
+    vi.clearAllTimers()
+    vi.useRealTimers()
+    clearAllSessionStates()
+  })
+
+  it('restores running sessions after reconnect without opening them', () => {
+    const now = 1_800_000_000_000
+
+    rehydrateLiveSessionStatuses(
+      {
+        sessions: [
+          {
+            id: 'runtime-overnight',
+            last_active: (now - SESSION_WATCHDOG_TIMEOUT_MS - 1_000) / 1000,
+            session_key: 'overnight-exam-learning',
+            status: 'working'
+          },
+          {
+            id: 'runtime-cleanup',
+            last_active: now / 1000,
+            session_key: 'temporary-file-cleanup',
+            status: 'working'
+          }
+        ]
+      },
+      now
+    )
+
+    expect($workingSessionIds.get()).toEqual(['overnight-exam-learning', 'temporary-file-cleanup'])
+    expect($stalledSessionIds.get()).toEqual(['overnight-exam-learning'])
+    expect($attentionSessionIds.get()).toEqual([])
+  })
+
+  it('restores a waiting turn as working and needing attention', () => {
+    rehydrateLiveSessionStatuses({
+      sessions: [{ id: 'runtime-needs-user', session_key: 'needs-user', status: 'waiting' }]
+    })
+
+    expect($workingSessionIds.get()).toEqual(['needs-user'])
+    expect($attentionSessionIds.get()).toEqual(['needs-user'])
+    expect($stalledSessionIds.get()).toEqual([])
+  })
+
+  it('ignores idle, starting, and malformed live-session rows', () => {
+    rehydrateLiveSessionStatuses({
+      sessions: [
+        { id: 'runtime-idle', session_key: 'idle-session', status: 'idle' },
+        { id: 'runtime-starting', session_key: 'starting-session', status: 'starting' },
+        { id: 'runtime-malformed', status: 'working' }
+      ]
+    })
+
+    expect($workingSessionIds.get()).toEqual([])
+    expect($attentionSessionIds.get()).toEqual([])
+    expect($stalledSessionIds.get()).toEqual([])
+  })
+})

apps/desktop/src/app/contrib/hooks/use-background-sync.ts

@@ -1,7 +1,14 @@
 import { useEffect } from 'react'
 
+import { createClientSessionState } from '@/lib/chat-runtime'
 import { refreshActiveProfile } from '@/store/profile'
 import { $activeSessionId, $currentCwd, setCurrentCwd } from '@/store/session'
+import {
+  $sessionStates,
+  publishSessionState,
+  SESSION_WATCHDOG_TIMEOUT_MS,
+  setSessionStalled
+} from '@/store/session-states'
 
 import type { GatewayRequester } from '../types'
 
@@ -11,8 +18,79 @@ import type { GatewayRequester } from '../types'
 const CRON_POLL_INTERVAL_MS = 30_000
 const MESSAGING_POLL_INTERVAL_MS = 10_000
 const ACTIVE_MESSAGING_SESSION_POLL_INTERVAL_MS = 5_000
+// Match the TUI's live-session refresh cadence. Auto-compression can rotate a
+// stored session id while its turn keeps running; until the next snapshot the
+// sidebar row points at the new id while the renderer still knows the old one.
+// A 15s cadence made that healthy transition look finished long enough to be
+// alarming (and clicking the row appeared to "fix" it by touching the live
+// session). This snapshot is small and already polled at 1.5s by the TUI.
+const LIVE_SESSION_STATUS_POLL_INTERVAL_MS = 1_500
+
+interface LiveSessionStatusItem {
+  id?: string
+  last_active?: number
+  session_key?: string
+  status?: 'idle' | 'starting' | 'waiting' | 'working'
+}
+
+interface LiveSessionStatusResponse {
+  sessions?: LiveSessionStatusItem[]
+}
+
+/** Restore sidebar liveness after a renderer/backend reconnect. Stream events
+ * normally own these states, but events emitted while Desktop was disconnected
+ * cannot be replayed. `session.active_list` is the authoritative in-memory
+ * snapshot and does not resume, focus, or otherwise mutate a chat. */
+export function rehydrateLiveSessionStatuses(response: LiveSessionStatusResponse, nowMs = Date.now()): void {
+  for (const session of response.sessions ?? []) {
+    const runtimeSessionId = session.id?.trim()
+    const storedSessionId = session.session_key?.trim()
+    const needsInput = session.status === 'waiting'
+    const working = session.status === 'working' || needsInput
+
+    if (!runtimeSessionId || !storedSessionId) {
+      continue
+    }
+
+    const existing = $sessionStates.get()[runtimeSessionId]
+
+    // Avoid re-arming the watchdog on every poll. Publish only when the
+    // authoritative live snapshot differs from the renderer mirror; normal
+    // gateway events continue to own subsequent transitions.
+    if (
+      !existing ||
+      existing.storedSessionId !== storedSessionId ||
+      existing.busy !== working ||
+      existing.needsInput !== needsInput
+    ) {
+      publishSessionState(runtimeSessionId, {
+        ...(existing ?? createClientSessionState(storedSessionId)),
+        busy: working,
+        needsInput,
+        storedSessionId
+      })
+    }
+
+    if (!working) {
+      setSessionStalled(storedSessionId, false)
+
+      continue
+    }
+
+    const lastActiveMs = Number(session.last_active) * 1000
+
+    const isQuiet =
+      session.status === 'working' &&
+      Number.isFinite(lastActiveMs) &&
+      lastActiveMs > 0 &&
+      nowMs - lastActiveMs >= SESSION_WATCHDOG_TIMEOUT_MS
+
+    setSessionStalled(storedSessionId, isQuiet)
+  }
+}
 
 interface BackgroundSyncParams {
+  activeGatewayProfile: string
   activeIsMessaging: boolean
   activeSessionId: null | string
   freshDraftReady: boolean
@@ -51,6 +129,7 @@ function visiblePoll(intervalMs: number, tick: () => void): () => void {
  * All the "the desktop websocket won't tell us, so poll" logic in one place.
  */
 export function useBackgroundSync({
+  activeGatewayProfile,
   activeIsMessaging,
   activeSessionId,
   freshDraftReady,
@@ -89,6 +168,49 @@ export function useBackgroundSync({
     }
   }, [gatewayState, refreshCurrentModel, refreshSessions, requestGateway])
 
+  // A reconnect loses renderer-only working/attention atoms while the backend
+  // keeps the actual turns alive. Re-seed from the gateway's in-memory session
+  // registry immediately, then cheaply poll while visible so a profile switch
+  // or missed reconnect edge cannot leave running rows dark until clicked.
+  useEffect(() => {
+    if (gatewayState !== 'open') {
+      return
+    }
+
+    let cancelled = false
+    let inFlight = false
+
+    const refreshLiveStatuses = async () => {
+      if (inFlight) {
+        return
+      }
+
+      inFlight = true
+
+      try {
+        const response = await requestGateway<LiveSessionStatusResponse>('session.active_list', {})
+
+        if (!cancelled) {
+          rehydrateLiveSessionStatuses(response)
+        }
+      } catch {
+        // Older gateways may not expose session.active_list. Live stream events
+        // still work as before; leave the current sidebar state untouched.
+      } finally {
+        inFlight = false
+      }
+    }
+
+    const dispose = visiblePoll(LIVE_SESSION_STATUS_POLL_INTERVAL_MS, () => void refreshLiveStatuses())
+
+    void refreshLiveStatuses()
+
+    return () => {
+      cancelled = true
+      dispose()
+    }
+  }, [activeGatewayProfile, gatewayState, requestGateway])
+
   // Keep the cron-jobs section live without a user action (scheduler ticks in
   // the background); re-check on tab re-focus too.
   useEffect(() => {