fix(frontend): make inbound forms accessible to screen readers (#7025)

Expose selectable options and selected values, associate validation guidance with controls, and contain keyboard focus in inbound dialogs. Preserve create and edit serialization and add Chromium keyboard and accessibility checks.

frontend/src/components/form/NativeSelect.css

@@ -0,0 +1,14 @@
+.native-select {
+  padding-inline: 11px;
+  font-family: inherit;
+  cursor: pointer;
+}
+
+.native-select:focus-visible {
+  outline: 2px solid currentColor;
+  outline-offset: 2px;
+}
+
+.native-select:disabled {
+  cursor: not-allowed;
+}