style: cover dialog should have a high z-index and admin OIDC auth button should be block style

addons/rose/addon/styles/rose/components/dialog/_cover.scss

@@ -2,6 +2,7 @@
   position: fixed;
   top: 0;
   left: 0;
+  z-index: 200;
   width: 100vw;
   height: 100vh;
   display: flex;
@@ -33,5 +34,6 @@
   top: 0;
   bottom: 0;
   right: 0;
+  z-index: 100;
   opacity: 0.85;
 }

ui/admin/app/styles/app.scss

@@ -138,6 +138,20 @@
   }
 }
 
+.rose-frame {
+  .rose-form-actions {
+    .rose-button-primary {
+      display: block;
+      margin: 0;
+      width: 100%;
+
+      .rose-button-wrapper {
+        display: inline;
+      }
+    }
+  }
+}
+
 .copyable {
   white-space: nowrap;