fix: canonicalize browser navigation after commit

apps/web/src/navigation/use-browser-pathname.test.tsx

@@ -4,12 +4,20 @@ import { afterEach, describe, expect, it, vi } from 'vitest';
 
 import { useBrowserPathname } from './use-browser-pathname.js';
 
-function Harness({ link = <a href="/automation">Automation</a> }: { link?: React.ReactNode }) {
-  const pathname = useBrowserPathname();
+function Harness({
+  link = <a href="/automation">Automation</a>,
+  onMainFocus,
+  resolvePathname,
+}: {
+  link?: React.ReactNode;
+  onMainFocus?: (pathname: string) => void;
+  resolvePathname?: (pathname: string) => string;
+}) {
+  const pathname = useBrowserPathname(resolvePathname);
   return (
     <>
       {link}
-      <main id="main-content" tabIndex={-1}>
+      <main id="main-content" tabIndex={-1} onFocus={() => onMainFocus?.(pathname)}>
         {pathname}
       </main>
     </>
@@ -27,7 +35,8 @@ describe('useBrowserPathname', () => {
     window.history.replaceState(null, '', '/fleet');
     const pushState = vi.spyOn(window.history, 'pushState');
     const scrollTo = vi.spyOn(window, 'scrollTo').mockImplementation(() => undefined);
-    render(<Harness />);
+    const focusedPathnames: string[] = [];
+    render(<Harness onMainFocus={(pathname) => focusedPathnames.push(pathname)} />);
 
     const link = screen.getByRole('link', { name: 'Automation' });
     const accepted = fireEvent.click(link);
@@ -36,9 +45,39 @@ describe('useBrowserPathname', () => {
     expect(pushState).toHaveBeenCalledWith(null, '', '/automation');
     expect(screen.getByRole('main').textContent).toBe('/automation');
     expect(document.activeElement).toBe(screen.getByRole('main'));
+    expect(focusedPathnames).toEqual(['/automation']);
     expect(scrollTo).toHaveBeenCalledWith({ top: 0, left: 0, behavior: 'auto' });
   });
 
+  it('replaces a legacy pathname with its canonical destination', () => {
+    window.history.replaceState(null, '', '/settings/instances');
+    const replaceState = vi.spyOn(window.history, 'replaceState');
+
+    render(
+      <Harness
+        resolvePathname={(pathname) =>
+          pathname === '/settings/instances' ? '/settings/system' : pathname
+        }
+      />,
+    );
+
+    expect(replaceState).toHaveBeenCalledWith(null, '', '/settings/system');
+    expect(window.location.pathname).toBe('/settings/system');
+    expect(screen.getByRole('main').textContent).toBe('/settings/system');
+  });
+
+  it('makes an exact-current link a no-op without adding history', () => {
+    window.history.replaceState(null, '', '/fleet');
+    const pushState = vi.spyOn(window.history, 'pushState');
+    render(<Harness link={<a href="/fleet">Current</a>} />);
+
+    const accepted = fireEvent.click(screen.getByRole('link', { name: 'Current' }));
+
+    expect(accepted).toBe(false);
+    expect(pushState).not.toHaveBeenCalled();
+    expect(window.location.pathname).toBe('/fleet');
+  });
+
   it('tracks browser history traversal and restores the page start', () => {
     window.history.replaceState(null, '', '/automation');
     const scrollTo = vi.spyOn(window, 'scrollTo').mockImplementation(() => undefined);