fix(dashboard): keep mobile nav visible on Android landscape and during keyboard

- Broaden mobile media query to include (max-height: 480px) so landscape
  phones (which exceed 768 CSS px wide) still render the bottom nav and
  mobile board layout instead of desktop horizontally-scrollable columns.
- Guard useMobileKeyboard against pinch-zoom (vv.scale > 1) — Android
  Chrome ignores user-scalable=no, and a focused textarea + zoom was
  false-positiving keyboard-open and hiding MobileNavBar.
- Read documentElement.clientHeight instead of stale window.innerHeight
  when computing keyboard overlap (Android multi-window can leave
  innerHeight cached at a wildly different value than the actual layout
  viewport — observed 2848 while html was 797).
- Add interactive-widget=resizes-content to the viewport meta so Android
  Chrome shrinks the layout viewport with the soft keyboard, matching iOS.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/dashboard/app/components/NewTaskModal.css

@@ -396,7 +396,7 @@
   color: var(--text);
 }
 
-@media (max-width: 768px) {
+@media (max-width: 768px), (max-height: 480px) {
   .workflow-step-order-actions .btn-icon {
     width: 36px;
     height: 36px;
@@ -424,7 +424,7 @@
   width: 100%;
 }
 
-@media (max-width: 768px) {
+@media (max-width: 768px), (max-height: 480px) {
   /* TaskForm: cap description textarea height on mobile, restore in fullscreen */
   .task-form-primary-section .description-with-refine textarea {
     max-height: 200px;