fix(mobile): keep long session titles on one header line

apps/mobile/src/components/agents/session-detail-content.test.ts

@@ -561,6 +561,10 @@ function page(
 // resolves with this cursor instead of the default `null`.
 let rootPageNextCursor: string | null = null;
 
+// Set before `mountDetails` by the long-title header tests; `fetchSession`
+// reports this session title instead of the short default.
+let sessionTitleOverride: string | null = null;
+
 function messageLists(renderer: ReactTestRenderer): ReactTestInstance[] {
   return renderer.root.findAll(node => Object.is(node.type, 'MessageList'));
 }
@@ -575,6 +579,7 @@ beforeEach(() => {
   globalContext.organizationId = 'global-org';
   globalContext.setOrganizationId.mockClear();
   rootPageNextCursor = null;
+  sessionTitleOverride = null;
   condensePreference.value = false;
   connectionHealth.isConnected = true;
   connectionHealth.reconnectExhausted = false;
@@ -662,7 +667,7 @@ async function mountDetails(
       return {
         kiloSessionId: id,
         cloudAgentSessionId: null,
-        title: `Root ${id}`,
+        title: sessionTitleOverride ?? `Root ${id}`,
         organizationId: null,
         gitUrl: null,
         gitBranch: null,
@@ -831,7 +836,7 @@ describe('SessionDetailContent display scope', () => {
     });
     const header = renderer.root.findByType(ScreenHeader);
     expect(header.findByProps({ accessibilityRole: 'header' }).props).toMatchObject({
-      numberOfLines: 2,
+      numberOfLines: 1,
       ellipsizeMode: 'tail',
     });
     expect(header.findByProps({ accessibilityRole: 'header' }).parent?.props.className).toContain(
@@ -857,6 +862,22 @@ describe('SessionDetailContent display scope', () => {
   });
 });
 
+describe('SessionDetailContent header title', () => {
+  // The title shares its row with a 44pt context pill and a copy action, so on
+  // a narrow phone the title column is a fraction of the row width. Letting the
+  // Text wrap there split a long word across two lines and truncated the second
+  // ("Moving-ave / rage empt…"). One line keeps the truncation at a clean tail
+  // ellipsis instead of breaking a word across two lines.
+  it('keeps a long session title on one line instead of breaking a word across two', async () => {
+    sessionTitleOverride = 'Moving-average rage empty baseline';
+    const { renderer } = await mountDetails();
+    const header = renderer.root.findByType(ScreenHeader);
+    const title = header.findByProps({ accessibilityRole: 'header' });
+    expect(title.props.numberOfLines).toBe(1);
+    expect(title.props.ellipsizeMode).toBe('tail');
+  });
+});
+
 describe('session detail status placement', () => {
   it.each(['progress', 'info'] as const)(
     'centers a %s status without transcript rows',
@@ -1445,7 +1466,7 @@ describe.each([true, false])('session detail return with history=%s', hasHistory
 
     const header = view.renderer.root.findByType(ScreenHeader);
     expect(header.findByProps({ accessibilityRole: 'header' }).props).toMatchObject({
-      numberOfLines: 2,
+      numberOfLines: 1,
       ellipsizeMode: 'tail',
     });
     expect(header.findByProps({ accessibilityRole: 'header' }).parent?.props.className).toContain(

apps/mobile/src/components/agents/session-detail-content.tsx

@@ -1876,6 +1876,7 @@ export function SessionDetailContent({
           ) : null}
           <ScreenHeader
             title={rename.title}
+            titleNumberOfLines={1}
             reserveTitleSpace
             backFallback="/(app)/(tabs)/(2_agents)"
             headerRight={headerRight}