fix(native-chat): focus the composer after a keyboard switch between chats (#29152)

The previous tab's hidden composer still held focus when the reveal hook ran,
and was treated as a live text field, so the new composer never got focus.

Fixes #28157

src/renderer/src/components/native-chat/native-chat-composer-reveal-focus.test.tsx

@@ -385,6 +385,21 @@ describe('useNativeChatComposerRevealFocus', () => {
     outside.remove()
   })
 
+  it('claims focus from the composer of the chat tab hidden by the same switch', () => {
+    const hiddenPane = document.createElement('div')
+    const previousComposer = document.createElement('textarea')
+    hiddenPane.appendChild(previousComposer)
+    document.body.appendChild(hiddenPane)
+    previousComposer.focus()
+    render({ isVisible: false, isFocusedGroup: true })
+    // Chromium leaves focus on the hidden field until a later task, after the reveal claim runs.
+    hiddenPane.setAttribute('inert', '')
+    render({ isVisible: true, isFocusedGroup: true })
+    drainFrames()
+    expect(container.querySelector('textarea')).toBe(document.activeElement)
+    hiddenPane.remove()
+  })
+
   it('still claims focus from the covered xterm helper textarea', () => {
     const helper = document.createElement('textarea')
     helper.className = 'xterm-helper-textarea'

src/renderer/src/components/terminal-pane/pane-helpers.ts

@@ -52,6 +52,10 @@ export function shouldPreserveEditableFocus(element: Element | null): boolean {
   if (element.classList.contains('xterm-helper-textarea') || element.closest('.xterm')) {
     return false
   }
+  // Why: a field in a just-hidden pane keeps focus until Chromium drops it to body a task later.
+  if (element.closest('[hidden], [inert]')) {
+    return false
+  }
   // Why: deferred fit/focus work can run after inline rename or settings
   // fields take focus. Layout maintenance must not blur user edits closed.
   return (