fix(FN-2838): prevent mobile zoom on dashboard form inputs

- Add global `touch-action: manipulation` on html/body to reduce gesture-triggered zoom
- Set mobile input font-size to 16px for terminal, nodes, and scripts modal form fields
- Extend mobile CSS regression tests to assert the global touch-action rule

packages/dashboard/app/components/NodesView.css

@@ -870,6 +870,7 @@
 
   .add-node-modal__field input {
     min-height: calc(var(--space-2xl) + var(--space-md));
+    font-size: 16px;
   }
 
   /* Instant transition on mobile for remote fields */