feat(desktop): add background-task indicator to sidebar session rows (#65174)

* feat(desktop): add background-task indicator to sidebar session rows

A session with a live terminal(background=true) process but no active LLM
turn now shows a pulsing gray dot in the sidebar — distinct from the accent
pulse of an active turn and the steady amber/green of needs-input/unread.

New $backgroundRunningSessionIds computed atom joins
$backgroundStatusBySession (runtime-keyed) with $sessionStates
(runtime→stored) to produce stored session ids the sidebar row can match
against — same pattern as $attentionSessionIds and $unreadFinishedSessionIds.

Also refactors SidebarRowDot from a 3-branch if-else chain into a
table-driven priority array of DotState entries. Each state declares its
active flag, className, ariaLabel, and title in one place — adding a new
indicator state is now one array entry instead of another conditional.

* fix(desktop): keep pulse-dot before:bg-* static so Tailwind emits it

The PING() helper interpolated the color into `before:bg-${color}`, but
Tailwind v4 only generates utilities it finds as complete static strings — a
template-composed `before:bg-(--ui-accent)` / `before:bg-muted-foreground/50`
is never emitted, so both pulse rings (working + new background) lost their
halo color. Make PING a static scaffold and write the before:bg color inline
per variant.

---------

Co-authored-by: Brooklyn Nicholson <brooklyn.bb.nicholson@gmail.com>

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

@@ -13,6 +13,7 @@ import { triggerHaptic } from '@/lib/haptics'
 import { handoffOriginSource, sessionSourceLabel } from '@/lib/session-source'
 import { coarseElapsed } from '@/lib/time'
 import { cn } from '@/lib/utils'
+import { $backgroundRunningSessionIds } from '@/store/composer-status'
 import { $attentionSessionIds, $unreadFinishedSessionIds } from '@/store/session'
 import { openSessionTile } from '@/store/session-states'
 import { canOpenSessionWindow, openSessionInNewWindow } from '@/store/windows'
@@ -80,6 +81,21 @@ export function SidebarSessionRow({
   // True when the session's most recent turn finished in the background (while
   // the user was viewing a different session) and hasn't been opened since.
   const isUnread = useStore($unreadFinishedSessionIds).includes(session.id)
+  // True when a terminal(background=true) process is alive in this session.
+  const hasBackground = useStore($backgroundRunningSessionIds).includes(session.id)
+
+  // 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'
 
   return (
     <SessionContextMenu
@@ -210,14 +226,12 @@ export function SidebarSessionRow({
               <SessionRowLeadDot
                 branchStem={branchStem}
                 className="transition-opacity group-hover/handle:opacity-0 group-focus-within/handle:opacity-0"
-                isWorking={isWorking}
-                needsInput={needsInput}
-                isUnread={isUnread}
+                dotState={dotState}
               />
             </SidebarRowGrab>
           ) : (
             <SidebarRowLead className={needsInput ? 'overflow-visible' : 'overflow-hidden'}>
-              <SessionRowLeadDot branchStem={branchStem} isWorking={isWorking} needsInput={needsInput} isUnread={isUnread} />
+              <SessionRowLeadDot branchStem={branchStem} dotState={dotState} />
             </SidebarRowLead>
           )}
           {handoffSource && handoffLabel ? (
@@ -238,17 +252,18 @@ 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,
-  isWorking,
-  needsInput = false,
-  isUnread = false,
+  dotState = 'idle',
   className
 }: {
   branchStem?: string
-  isWorking: boolean
-  needsInput?: boolean
-  isUnread?: boolean
+  dotState?: SessionDotState
   className?: string
 }) {
   return (
@@ -258,66 +273,77 @@ function SessionRowLeadDot({
           {branchStem}
         </span>
       ) : null}
-      <SidebarRowDot isWorking={isWorking} needsInput={needsInput} isUnread={isUnread} />
+      <SidebarRowDot dotState={dotState} />
     </span>
   )
 }
 
-function SidebarRowDot({
-  isWorking,
-  needsInput = false,
-  isUnread = false,
-  className
-}: {
-  isWorking: boolean
-  needsInput?: boolean
-  isUnread?: boolean
-  className?: string
-}) {
+// A pure lookup table: each state maps to its className, aria-label, and
+// title. No priority resolution here — the call site already picked one.
+// Label/title are resolved from sidebar.row translations, keyed by name.
+type DotVariant = {
+  ariaLabel?: (r: Translations['sidebar']['row']) => string
+  className: string
+  role?: 'status'
+  title?: (r: Translations['sidebar']['row']) => string
+}
+
+// Shared base for every active dot; idle is smaller and uses its own class.
+const DOT_BASE = 'relative size-1.5 rounded-full'
+
+// Pseudo-element ping ring that scales outward and fades — shared scaffold for
+// the two pulsing dots. The `before:bg-*` color is written inline per variant
+// (NOT interpolated here): Tailwind only generates utilities it can see as
+// complete static strings, so a `before:bg-${color}` template never emits.
+const PING = "before:absolute before:inset-0 before:animate-ping before:rounded-full before:content-['']"
+
+const DOT_VARIANTS: Record<SessionDotState, DotVariant> = {
+  // Amber steady — a clarify/approval is blocking the turn. Steady (not
+  // pulsing) reads as "your turn", distinct from the accent pulse of a turn.
+  'needs-input': {
+    ariaLabel: r => r.needsInput,
+    className: `${DOT_BASE} quest-glow bg-amber-500`,
+    role: 'status',
+    title: r => r.waitingForAnswer
+  },
+  // Accent pulse — the LLM turn is actively running.
+  working: {
+    ariaLabel: r => r.sessionRunning,
+    className: `${DOT_BASE} bg-(--ui-accent) shadow-[0_0_0.625rem_color-mix(in_srgb,var(--ui-accent)_55%,transparent)] ${PING} before:bg-(--ui-accent) before:opacity-70`,
+    role: 'status'
+  },
+  // Pulsing gray — a terminal(background=true) process is alive while the LLM
+  // is idle. Gray (not accent) reads as "something chugging along".
+  background: {
+    ariaLabel: r => r.backgroundRunning,
+    className: `${DOT_BASE} bg-muted-foreground/50 ${PING} before:bg-muted-foreground/50 before:opacity-50`,
+    role: 'status',
+    title: r => r.backgroundRunning
+  },
+  // Steady green — a background session's turn completed and the user hasn't
+  // opened it since. "Something new here, go look."
+  unread: {
+    ariaLabel: r => r.finishedUnread,
+    className: `${DOT_BASE} bg-emerald-500`,
+    role: 'status',
+    title: r => r.finishedUnread
+  },
+  idle: {
+    className: 'size-1 rounded-full bg-(--ui-text-quaternary) opacity-80'
+  }
+}
+
+function SidebarRowDot({ dotState, className }: { dotState: SessionDotState; className?: string }) {
   const { t } = useI18n()
   const r = t.sidebar.row
-
-  // "Needs input" wins over "working": a clarify-blocked session is technically
-  // still running, but the actionable state is that it's waiting on the user.
-  // Amber + steady (no ping) reads as "your turn", distinct from the accent
-  // pulse of an active turn.
-  if (needsInput) {
-    return (
-      <span
-        aria-label={r.needsInput}
-        className={cn('quest-glow relative size-1.5 rounded-full bg-amber-500', className)}
-        role="status"
-        title={r.waitingForAnswer}
-      />
-    )
-  }
-
-  // "Unread finished" wins over the default gray dot: a background session's
-  // turn completed and the user hasn't opened it since. Steady green (no pulse)
-  // reads as "something new here, go look" — distinct from the live accent
-  // pulse of a running turn.
-  if (isUnread) {
-    return (
-      <span
-        aria-label={r.finishedUnread}
-        className={cn('size-1.5 rounded-full bg-emerald-500', className)}
-        role="status"
-        title={r.finishedUnread}
-      />
-    )
-  }
+  const variant = DOT_VARIANTS[dotState]
 
   return (
     <span
-      aria-label={isWorking ? r.sessionRunning : undefined}
-      className={cn(
-        'rounded-full',
-        isWorking
-          ? "relative size-1.5 bg-(--ui-accent) shadow-[0_0_0.625rem_color-mix(in_srgb,var(--ui-accent)_55%,transparent)] before:absolute before:inset-0 before:animate-ping before:rounded-full before:bg-(--ui-accent) before:opacity-70 before:content-['']"
-          : 'size-1 bg-(--ui-text-quaternary) opacity-80',
-        className
-      )}
-      role={isWorking ? 'status' : undefined}
+      aria-label={variant.ariaLabel?.(r)}
+      className={cn(variant.className, className)}
+      role={variant.role}
+      title={variant.title?.(r)}
     />
   )
 }

apps/desktop/src/i18n/en.ts

@@ -1656,6 +1656,7 @@ export const en: Translations = {
       needsInput: 'Needs your input',
       waitingForAnswer: 'Waiting for your answer',
       finishedUnread: 'Finished — unread',
+      backgroundRunning: 'Background task running',
       handoffOrigin: platform => `Handed off from ${platform}`,
       renamed: 'Renamed',
       renameFailed: 'Rename failed',

apps/desktop/src/i18n/ja.ts

@@ -1574,6 +1574,7 @@ export const ja = defineLocale({
       needsInput: '入力が必要です',
       waitingForAnswer: '回答を待っています',
       finishedUnread: '完了 — 未読',
+      backgroundRunning: 'バックグラウンドタスク実行中',
       handoffOrigin: platform => `${platform} から引き継ぎ`,
       renamed: '名前を変更しました',
       renameFailed: '名前の変更に失敗しました',

apps/desktop/src/i18n/types.ts

@@ -1379,6 +1379,7 @@ export interface Translations {
       needsInput: string
       waitingForAnswer: string
       finishedUnread: string
+      backgroundRunning: string
       handoffOrigin: (platform: string) => string
       renamed: string
       renameFailed: string

apps/desktop/src/i18n/zh-hant.ts

@@ -1524,6 +1524,7 @@ export const zhHant = defineLocale({
       needsInput: '需要您的輸入',
       waitingForAnswer: '等待您的回答',
       finishedUnread: '已完成 — 未讀',
+      backgroundRunning: '背景任務執行中',
       handoffOrigin: platform => `從 ${platform} 轉接`,
       renamed: '已重新命名',
       renameFailed: '重新命名失敗',

apps/desktop/src/i18n/zh.ts

@@ -1832,6 +1832,7 @@ export const zh: Translations = {
       needsInput: '需要你输入',
       waitingForAnswer: '正在等待你的回答',
       finishedUnread: '已完成 — 未读',
+      backgroundRunning: '后台任务运行中',
       handoffOrigin: platform => `从 ${platform} 转接`,
       renamed: '已重命名',
       renameFailed: '重命名失败',

apps/desktop/src/store/composer-status.ts

@@ -6,6 +6,7 @@ import type { TodoItem, TodoStatus } from '@/lib/todos'
 import { $gateway } from './gateway'
 import { dispatchNativeNotification } from './native-notifications'
 import { notifyError } from './notifications'
+import { $sessionStates } from './session-states'
 import { $subagentsBySession, type SubagentProgress } from './subagents'
 import { $todosBySession } from './todos'
 
@@ -35,6 +36,35 @@ export interface ComposerStatusItem {
 // registry (`terminal(background=true)` spawns) via `process.list`.
 export const $backgroundStatusBySession = atom<Record<string, ComposerStatusItem[]>>({})
 
+// Stored session ids that have at least one RUNNING background process. The
+// sidebar row reads this for a pulsing gray dot — distinct from the accent
+// pulse of an active LLM turn — so the user can tell at a glance "this session
+// has something chugging along in the background" even when the turn is idle.
+//
+// $backgroundStatusBySession is keyed by RUNTIME session id (gateway events
+// and process.list both speak that); the sidebar row knows only the STORED id.
+// $sessionStates bridges the two: runtime id → state.storedSessionId.
+export const $backgroundRunningSessionIds = computed(
+  [$backgroundStatusBySession, $sessionStates],
+  (bg, states) => {
+    const ids = new Set<string>()
+
+    for (const [runtimeId, items] of Object.entries(bg)) {
+      if (!items.some(i => i.state === 'running')) {
+        continue
+      }
+
+      const storedId = states[runtimeId]?.storedSessionId
+
+      if (storedId) {
+        ids.add(storedId)
+      }
+    }
+
+    return [...ids]
+  }
+)
+
 // Rows the user X-ed away. The registry keeps finished processes around for a
 // while, so without this every refresh would resurrect a dismissed row.
 const dismissedBySession = new Map<string, Set<string>>()