Restore per-interface domain resolvers

tests/luci_interface_settings.sh

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+set -eo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+SECTION_JS="$ROOT_DIR/luci-app-forkop/htdocs/luci-static/resources/view/forkop/section.js"
+
+fail() {
+  printf 'FAIL: %s\n' "$1" >&2
+  exit 1
+}
+
+grep -Fq 'function dnsTypeChoices() {' "$SECTION_JS" ||
+  fail "network interface settings must define DNS protocol choices"
+grep -Fq 'dnsTypeChoices().forEach((choice) => o.value(choice.value, choice.label));' "$SECTION_JS" ||
+  fail "network interface settings must populate the DNS protocol field"
+grep -Fq 'o.renderItemSettingsModal = showInterfaceSettingsModal;' "$SECTION_JS" ||
+  fail "network interfaces must keep their settings modal handler"
+
+printf 'LuCI network interface settings checks passed\n'