fix: show page title in popup title bar instead of doubling the origin

The native title bar and the origin bar both showed the origin, reading
as a doubled header. Match Chrome popup behavior: title bar shows the
page title (reset to origin on navigation so a stale title cannot
outlive its origin); the origin bar below remains the unspoofable trust
surface.

Co-authored-by: Orca <help@stably.ai>

src/main/browser/popup-origin-bar-window.test.ts

@@ -253,6 +253,23 @@ describe('openPopupWithOriginBar', () => {
     expect(lastWindow().setTitle).toHaveBeenCalledWith('http://phish.example.net')
   })
 
+  it('shows the page title in the native title bar but resets to origin on navigation', () => {
+    const adopted = createFakeWebContents()
+    openPopupWithOriginBar(
+      { webContents: adopted as never },
+      'https://accounts.example.com/oauth?code=SECRET'
+    )
+    // Until the page supplies a title, the window title is the origin.
+    expect(lastWindow().options.title).toBe('https://accounts.example.com')
+
+    adopted.emit('page-title-updated', {}, 'Sign in to Example')
+    expect(lastWindow().setTitle).toHaveBeenLastCalledWith('Sign in to Example')
+
+    // A stale title must not survive a cross-origin navigation.
+    adopted.emit('did-navigate', {}, 'https://evil.example.net/')
+    expect(lastWindow().setTitle).toHaveBeenLastCalledWith('https://evil.example.net')
+  })
+
   it('closes the window when the popup content is destroyed', () => {
     const adopted = createFakeWebContents()
     openPopupWithOriginBar({ webContents: adopted as never }, 'https://example.com/')

src/main/browser/popup-origin-bar-window.ts

@@ -139,6 +139,10 @@ export function openPopupWithOriginBar(
   let currentUrl = initialUrl
   const renderOrigin = (): void => {
     const { label, insecure } = describePopupOrigin(currentUrl)
+    // Why: origin is the title only until the page supplies one — the bar
+    // below stays the trust surface, so the native title bar can show the
+    // page title (Chrome popup behavior) instead of doubling the origin.
+    // Re-asserting on navigation stops a stale title outliving its origin.
     if (!window.isDestroyed()) {
       window.setTitle(label)
     }
@@ -161,6 +165,12 @@ export function openPopupWithOriginBar(
     renderOrigin()
   }
   contentWebContents.on('did-navigate', handleDidNavigate)
+  const handlePageTitleUpdated = (_event: Electron.Event, title: string): void => {
+    if (!window.isDestroyed() && title) {
+      window.setTitle(title)
+    }
+  }
+  contentWebContents.on('page-title-updated', handlePageTitleUpdated)
 
   // Why: with no adopted contents there is no Chromium-driven navigation for
   // this popup, so load the target ourselves (opener handle is already gone).
@@ -179,6 +189,7 @@ export function openPopupWithOriginBar(
     if (!contentWebContents.isDestroyed()) {
       contentWebContents.off('destroyed', handleContentDestroyed)
       contentWebContents.off('did-navigate', handleDidNavigate)
+      contentWebContents.off('page-title-updated', handlePageTitleUpdated)
       // Why: close() (not destroy) so the page's unload handlers run — OAuth
       // pages often notify the opener from unload.
       contentWebContents.close()