FN-5673: keep mobile nav and footer pinned when keyboard opens

Prevent keyboard viewport shifts from displacing mobile bottom bars while preserving iOS hide safeguards.

- Split executor footer keyboard behavior into separate hide and pinning controls
- Add keyboard-open CSS overrides to keep mobile nav/footer bottom at 0 instead of offsetting upward
- Wire App to pass distinct keyboard props and expand component/CSS contract tests for keyboard-open classes and rule ordering

Files changed:
 packages/dashboard/app/App.tsx                     |  3 ++-
 packages/dashboard/app/__tests__/mobile-bottom-bars-keyboard-layout.test.ts | 30 ++++++++++++++++++++++
 packages/dashboard/app/components/ExecutorStatusBar.css |  6 +++++
 packages/dashboard/app/components/ExecutorStatusBar.tsx | 14 +++++-----
 packages/dashboard/app/components/MobileNavBar.css |  3 ++-
 packages/dashboard/app/components/__tests__/ExecutorStatusBar.test.tsx | 17 ++++++++++++
 packages/dashboard/app/components/__tests__/MobileNavBar.test.tsx |  6 +++--
 7 files changed, 69 insertions(+), 10 deletions(-)

Fusion-Task-Id: FN-5673

Fusion-Task-Lineage: 7c2dc749-214a-48ab-af58-5638ea27ae47

packages/dashboard/app/components/MobileNavBar.css

@@ -48,7 +48,8 @@
      compensation that would otherwise push the bar up by the keyboard
      height (iOS shrinks vv.height; bottomOffset becomes ~keyboard height).
      Pin the nav to the page bottom so the keyboard simply covers it. */
-  .mobile-nav-bar--keyboard-open {
+  .mobile-nav-bar.mobile-nav-bar--keyboard-open,
+  .mobile-nav-bar.mobile-nav-bar--with-footer.mobile-nav-bar--keyboard-open {
     bottom: 0;
   }