feat(sessions): show a pending-question indicator on session rows

Adds a per-session pending-question badge to sidebar rows, driven by the
live directory-store question state through a dedicated per-session
subscription channel so unrelated streaming never re-renders rows.

Collapsed parent rows roll up pending questions of hidden descendants
from their owning directory stores without bootstrapping them. Question
state is cloned on session delete/archive so badges clear when sessions
disappear. Adds the questionChangeCallbacks sync performance counter,
i18n keys for all locales, and unit tests for the subscription channel
and scope selection.

Fixes #2634

packages/ui/src/components/session/sidebar/DOCUMENTATION.md

@@ -32,7 +32,7 @@
 - `SidebarFooter.tsx`: Static footer with icon-only settings, shortcuts, and about actions.
 - `SidebarProjectsList.tsx`: Main scrollable renderer for project zones and their flat/archived groups plus empty/search states; owns project drag-to-reorder.
 - `SessionGroupSection.tsx`: Renders one flat (or archived) group: sessions first, then flat folder entries with path labels, show-more batching, and explicit loading/error/retry state for empty groups. Archived buckets (VS Code) virtualize past 50 rows.
-- `SessionNodeItem.tsx`: Renders one session row/tree node with a single-line layout, inline branch label, indicators, menu actions, and nested children. Rows do not initiate directory bootstrap on mount.
+- `SessionNodeItem.tsx`: Renders one session row/tree node with a single-line layout, inline branch label, indicators, menu actions, and nested children. Pending-question counts stay per-session while expanded and roll up hidden descendants from their owning directory stores while collapsed. Rows do not initiate directory bootstrap on mount.
 - `collapsedActivityIndicator.tsx`: Aggregate busy/unseen dot for collapsed groups and folders.
 - `ConfirmDialogs.tsx`: Shared confirm dialog wrappers for session delete and folder delete flows.
 - `sortableItems.tsx`: DnD sortable wrapper for project ordering plus the sticky zone-band project header and its action affordances.

packages/ui/src/components/session/sidebar/SessionNodeItem.tsx

@@ -22,11 +22,11 @@ import { isSessionPinned, type SessionPinnedTarget } from '@/stores/useSessionPi
 import { Icon } from "@/components/icon/Icon";
 import { buildExportFilename, downloadAsMarkdown, formatSessionAsMarkdown, getExportRevealLabelKey, revealExportedMarkdown, saveAsMarkdownDesktop } from '@/lib/exportSession';
 import type { ChildSessionExport } from '@/lib/exportSession';
-import { buildSessionMessageRecordsSnapshot, useDirectoryStore, useGlobalSessionStatus, useSessionPermissions } from '@/sync/sync-context';
+import { buildSessionMessageRecordsSnapshot, useDirectoryStore, useGlobalSessionStatus, useSessionPermissions, useSessionQuestionCount } from '@/sync/sync-context';
 import { useSync } from '@/sync/use-sync';
 import { useViewportStore, viewportSessionKey } from '@/sync/viewport-store';
 import { DraggableSessionRow } from './sessionFolderDnd';
-import { nodeContainsSessionId, nodeHasPinnedMembershipChange } from './sessionNodeItemUtils';
+import { nodeContainsSessionId, nodeHasPinnedMembershipChange, selectQuestionBadgeSessionScopes } from './sessionNodeItemUtils';
 import type { SessionNodeChildRenderExtras, SessionNodeRenderExtras } from './sessionNodeItemUtils';
 import type { SessionNode } from './types';
 import { formatProjectLabel, formatSessionCompactDateLabel, formatSessionDateLabel, normalizePath, renderHighlightedText } from './utils';
@@ -470,6 +470,11 @@ function SessionNodeItemComponent(props: Props): React.ReactNode {
   // expand the other. Matches the format of menuInstanceKey.
   const expansionKey = menuInstanceKey;
   const isExpanded = hasSessionSearchQuery ? true : expandedParents.has(expansionKey);
+  const questionBadgeSessionScopes = React.useMemo(
+    () => selectQuestionBadgeSessionScopes(node, isExpanded, sessionDirectory),
+    [isExpanded, node, sessionDirectory],
+  );
+  const pendingQuestionCount = useSessionQuestionCount(questionBadgeSessionScopes);
   const isSubtaskSession = Boolean((resolvedSession as Session & { parentID?: string | null }).parentID);
   const unseenCount = useSessionUnseenCount(session.id);
   const needsAttention = unseenCount > 0 && (!isSubtaskSession || notifyOnSubtasks);
@@ -676,6 +681,9 @@ function SessionNodeItemComponent(props: Props): React.ReactNode {
   }
 
   const pendingPermissionCount = sessionPermissions.length;
+  const pendingQuestionLabel = pendingQuestionCount === 1
+    ? t('sessions.sidebar.session.status.questionPendingSingle')
+    : t('sessions.sidebar.session.status.questionPendingMany', { count: pendingQuestionCount });
   const showUnreadStatus = !isMovingToWorktree && !isStreaming && needsAttention && !isActive;
   const showStatusMarker = isStreaming || showUnreadStatus;
   // Both states are the same static dot; only the color separates "running"
@@ -1292,6 +1300,12 @@ function SessionNodeItemComponent(props: Props): React.ReactNode {
                           <span className="leading-none">{pendingPermissionCount}</span>
                         </span>
                       ) : null}
+                      {pendingQuestionCount > 0 ? (
+                        <span className="inline-flex items-center gap-1 rounded bg-status-info/10 px-1 py-0.5 text-[0.7rem] text-status-info flex-shrink-0" title={pendingQuestionLabel} aria-label={pendingQuestionLabel}>
+                          <Icon name="question" className="h-3 w-3" />
+                          <span className="leading-none">{pendingQuestionCount}</span>
+                        </span>
+                      ) : null}
                     </div>
                   </button>
                 </TooltipTrigger>

packages/ui/src/components/session/sidebar/sessionNodeItemUtils.test.ts

@@ -2,7 +2,7 @@ import { describe, expect, test } from 'bun:test';
 import type { Session } from '@opencode-ai/sdk/v2';
 import { getRuntimeKey } from '@/lib/runtime-switch';
 import { getPinnedSessionKey } from '@/stores/useSessionPinnedStore';
-import { computeNodeStructureKey, nodeHasPinnedMembershipChange, selectFolderRootNodes } from './sessionNodeItemUtils';
+import { computeNodeStructureKey, nodeHasPinnedMembershipChange, selectFolderRootNodes, selectQuestionBadgeSessionScopes } from './sessionNodeItemUtils';
 import type { SessionNode } from './types';
 
 const session = (id: string, title: string): Session => ({
@@ -32,6 +32,41 @@ describe('computeNodeStructureKey', () => {
   });
 });
 
+describe('selectQuestionBadgeSessionScopes', () => {
+  const withDirectory = (node: SessionNode, directory: string | null): SessionNode => ({
+    ...node,
+    session: { ...node.session, directory } as Session,
+  });
+
+  test('rolls up the hidden subtree by owning directory when a parent is collapsed', () => {
+    const grandchild = withDirectory({ session: session('grandchild', 'Grandchild'), children: [], worktree: null }, '/worktrees/feature');
+    const child = withDirectory({ session: session('child', 'Child'), children: [grandchild], worktree: null }, '/worktrees/feature');
+    const root = withDirectory({ session: session('root', 'Root'), children: [child], worktree: null }, '/repo');
+
+    expect(selectQuestionBadgeSessionScopes(root, false, '/repo')).toEqual([
+      { directory: '/repo', sessionIDs: ['root'] },
+      { directory: '/worktrees/feature', sessionIDs: ['child', 'grandchild'] },
+    ]);
+  });
+
+  test('keeps expanded rows accurate to their own session only', () => {
+    const child = withDirectory({ session: session('child', 'Child'), children: [], worktree: null }, '/worktrees/feature');
+    const root = withDirectory({ session: session('root', 'Root'), children: [child], worktree: null }, '/repo');
+
+    expect(selectQuestionBadgeSessionScopes(root, true, '/repo')).toEqual([
+      { directory: '/repo', sessionIDs: ['root'] },
+    ]);
+  });
+
+  test('falls back to the group directory when the session has none', () => {
+    const root: SessionNode = { session: session('root', 'Root'), children: [], worktree: null };
+
+    expect(selectQuestionBadgeSessionScopes(root, false, '/fallback')).toEqual([
+      { directory: '/fallback', sessionIDs: ['root'] },
+    ]);
+  });
+});
+
 describe('nodeHasPinnedMembershipChange', () => {
   test('detects composite pin changes using the group directory fallback', () => {
     const node: SessionNode = {

packages/ui/src/components/session/sidebar/sessionNodeItemUtils.ts

@@ -1,4 +1,6 @@
 import { getRuntimeKey } from '@/lib/runtime-switch';
+import { normalizePath } from '@/lib/pathNormalization';
+import { resolveGlobalSessionDirectory } from '@/stores/useGlobalSessionsStore';
 import { getPinnedSessionKey } from '@/stores/useSessionPinnedStore';
 import type { SessionNode } from './types';
 
@@ -70,6 +72,41 @@ export const nodeContainsSessionId = (node: SessionNode, sessionId: string | nul
   return false;
 };
 
+export type QuestionBadgeSessionScope = {
+  directory: string;
+  sessionIDs: string[];
+};
+
+/**
+ * Choose which (directory, sessionIDs) scopes a sidebar row's pending-question
+ * badge should count. An expanded row counts only its own session; a collapsed
+ * parent row additionally rolls up the hidden descendants of its subtree,
+ * grouped by the directory store each descendant actually lives in, so badges
+ * stay correct for worktree/subtask sessions without bootstrapping their
+ * directory stores.
+ */
+export const selectQuestionBadgeSessionScopes = (
+  node: SessionNode,
+  isExpanded: boolean,
+  fallbackDirectory: string | null,
+): QuestionBadgeSessionScope[] => {
+  const sessionIDsByDirectory = new Map<string, string[]>();
+  const visit = (current: SessionNode): void => {
+    const directory = resolveGlobalSessionDirectory(current.session)
+      ?? normalizePath(current.worktree?.path)
+      ?? fallbackDirectory;
+    if (directory) {
+      const sessionIDs = sessionIDsByDirectory.get(directory) ?? [];
+      sessionIDs.push(current.session.id);
+      sessionIDsByDirectory.set(directory, sessionIDs);
+    }
+    if (current === node && isExpanded) return;
+    for (const child of current.children) visit(child);
+  };
+  visit(node);
+  return [...sessionIDsByDirectory].map(([directory, sessionIDs]) => ({ directory, sessionIDs }));
+};
+
 export const selectFolderRootNodes = (
   sessionIds: string[],
   nodeBySessionId: ReadonlyMap<string, SessionNode>,