fix(ios): keep note editor controls above virtual keyboard

The CDK overlay container does not shrink with Capacitor's resize:'native'
mode on iOS, so position:fixed dialogs extend behind the virtual keyboard,
hiding the Save/Close buttons.

- Subtract --keyboard-height from the fullscreen markdown dialog height when
  the iOS keyboard is visible, keeping controls above the keyboard
- Enable the native iOS accessory bar so a "Done" button appears above the
  keyboard, giving users a clear dismiss affordance

src/app/core/theme/global-theme.service.ts

@@ -469,6 +469,9 @@ export class GlobalThemeService {
    * Adds/removes CSS classes when keyboard shows/hides.
    */
   private _initIOSKeyboardHandling(): void {
+    // Show the native iOS accessory bar ("Done" button) above the keyboard
+    Keyboard.setAccessoryBarVisible({ isVisible: true });
+
     Keyboard.addListener('keyboardWillShow', (info: KeyboardInfo) => {
       Log.log('iOS keyboard will show', info);
       this.document.body.classList.add(BodyClass.isKeyboardVisible);

src/app/ui/dialog-fullscreen-markdown/dialog-fullscreen-markdown.component.scss

@@ -18,6 +18,13 @@
   padding-top: var(--mac-title-bar-padding);
 }
 
+// On iOS, the virtual keyboard overlaps position:fixed elements since the CDK
+// overlay container does not shrink with Capacitor's resize:'native' mode.
+// Subtract the keyboard height so Save/Close buttons stay above the keyboard.
+:host-context(body.isNativeMobile.isKeyboardVisible) {
+  height: calc(100% - var(--keyboard-height, 0px));
+}
+
 .formatting-toolbar {
   display: flex;
   flex-wrap: nowrap;