fix(android): the detail panel can no longer be dragged sideways

The editing row kept the full-width field and set three buttons beside
it, so the line was wider than the frame. A pane scrollable on one axis
is scrollable on both - the specification turns the untouched axis into
`auto` - so the overflow was draggable, and the keyboard's Enter key
brought the field back into view, taking the whole panel with it.

The field now shares its line, and no pane scrolls sideways. Enter
validates, which is what the key was pressed for.

android-client/web/app.html

@@ -67,7 +67,8 @@
   body.on-detail #list   { transform: translateX(-22%); }
   body.on-detail #detail { transform: translateX(0); }
 
-  .scroll { flex: 1; overflow-y: auto; -webkit-overflow-scrolling: touch;
+  .scroll { flex: 1; overflow-y: auto; overflow-x: hidden;
+            -webkit-overflow-scrolling: touch;
             overscroll-behavior: contain; padding: 0 12px 16px; }
 
   /* --- barre de recherche ------------------------------------------------ */
@@ -585,13 +586,19 @@ function openEditor(k) {
   line.innerHTML =
       '<input class="field-in" id="editval" type="password" autocomplete="off"'
     + ' autocorrect="off" autocapitalize="none" spellcheck="false"'
-    + ' style="margin:0">'
+    + ' style="margin:0;flex:1;min-width:0;width:auto">'
     + '<button class="btn" data-editshow>Show</button>'
     + '<button class="btn" data-editcancel>Cancel</button>'
     + '<button class="btn main" data-editsave>Save</button>';
   var input = document.getElementById('editval');
   input.value = detailRows[k].v;
   input.focus();
+  input.addEventListener('keydown', function (ev) {
+    if (ev.key !== 'Enter') return;
+    ev.preventDefault();
+    var save = document.querySelector('[data-editsave]');
+    if (save && !save.disabled) save.click();
+  });
   send('touch');
 }