fix(tabs): scroll file preview tabs into view when selected

The TabBar scroll-into-view effect only triggered for AI tabs. Added
activeFileTabId to the useEffect dependencies so file preview tabs
are also scrolled into view when opened.

src/__tests__/renderer/components/TabBar.test.tsx

@@ -1527,6 +1527,70 @@ describe('TabBar', () => {
 
 			rafSpy.mockRestore();
 		});
+
+		it('scrolls to center file tab when activeFileTabId changes', async () => {
+			// Mock requestAnimationFrame
+			const rafSpy = vi.spyOn(window, 'requestAnimationFrame').mockImplementation((cb) => {
+				cb(0);
+				return 0;
+			});
+			const scrollToSpy = vi.fn();
+
+			const tabs = [createTab({ id: 'tab-1', name: 'Tab 1' })];
+			const fileTab: FilePreviewTab = {
+				id: 'file-1',
+				path: '/path/to/file.ts',
+				name: 'file',
+				extension: '.ts',
+			};
+			const unifiedTabs = [
+				{ id: 'tab-1', type: 'ai' as const, data: tabs[0] },
+				{ id: 'file-1', type: 'file' as const, data: fileTab },
+			];
+
+			const { rerender, container } = render(
+				<TabBar
+					tabs={tabs}
+					activeTabId="tab-1"
+					theme={mockTheme}
+					onTabSelect={mockOnTabSelect}
+					onTabClose={mockOnTabClose}
+					onNewTab={mockOnNewTab}
+					unifiedTabs={unifiedTabs}
+					activeFileTabId={null}
+					onFileTabSelect={vi.fn()}
+					onFileTabClose={vi.fn()}
+				/>
+			);
+
+			// Mock scrollTo on the container
+			const tabBarContainer = container.firstChild as HTMLElement;
+			tabBarContainer.scrollTo = scrollToSpy;
+
+			// Clear initial calls
+			scrollToSpy.mockClear();
+
+			// Select the file tab - this should trigger scroll to file tab
+			rerender(
+				<TabBar
+					tabs={tabs}
+					activeTabId="tab-1"
+					theme={mockTheme}
+					onTabSelect={mockOnTabSelect}
+					onTabClose={mockOnTabClose}
+					onNewTab={mockOnNewTab}
+					unifiedTabs={unifiedTabs}
+					activeFileTabId="file-1"
+					onFileTabSelect={vi.fn()}
+					onFileTabClose={vi.fn()}
+				/>
+			);
+
+			// scrollTo should have been called when file tab was selected
+			expect(scrollToSpy).toHaveBeenCalled();
+
+			rafSpy.mockRestore();
+		});
 	});
 
 	describe('styling', () => {

src/renderer/components/TabBar.tsx

@@ -1598,12 +1598,14 @@ function TabBarInner({
 	const tabRefs = useRef<Map<string, HTMLDivElement>>(new Map());
 	const [isOverflowing, setIsOverflowing] = useState(false);
 
-	// Center the active tab in the scrollable area when activeTabId changes or filter is toggled
+	// Center the active tab in the scrollable area when activeTabId or activeFileTabId changes, or filter is toggled
 	useEffect(() => {
 		requestAnimationFrame(() => {
 			const container = tabBarRef.current;
+			// When a file tab is active, scroll to it; otherwise scroll to the active AI tab
+			const targetTabId = activeFileTabId || activeTabId;
 			const tabElement = container?.querySelector(
-				`[data-tab-id="${activeTabId}"]`
+				`[data-tab-id="${targetTabId}"]`
 			) as HTMLElement | null;
 			if (container && tabElement) {
 				// Calculate scroll position to center the tab
@@ -1612,7 +1614,7 @@ function TabBarInner({
 				container.scrollTo({ left: scrollLeft, behavior: 'smooth' });
 			}
 		});
-	}, [activeTabId, showUnreadOnly]);
+	}, [activeTabId, activeFileTabId, showUnreadOnly]);
 
 	// Can always close tabs - closing the last one creates a fresh new tab
 	const canClose = true;