feat(wpmc S4): Helpers::index_town_alt_page_id reads ACF option

includes/class-helpers.php

@@ -102,6 +102,16 @@ final class Helpers
         return $path . $query . $fragment;
     }
 
+    public static function index_town_alt_page_id(): ?int
+    {
+        if (!\function_exists('get_field')) {
+            return null;
+        }
+        $value = \get_field('index_town_alt', 'option');
+        $id = (int) $value;
+        return $id > 0 ? $id : null;
+    }
+
     public static function main_town_slug(): ?string
     {
         if (!\function_exists('get_field')) {

tests/HelpersTest.php

@@ -311,4 +311,24 @@ final class HelpersTest extends TestCase
 
         self::assertTrue(true);
     }
+
+    public function test_index_town_alt_page_id_returns_int_when_option_set(): void
+    {
+        \Brain\Monkey\Functions\expect('get_field')
+            ->once()
+            ->with('index_town_alt', 'option')
+            ->andReturn(42);
+
+        self::assertSame(42, Helpers::index_town_alt_page_id());
+    }
+
+    public function test_index_town_alt_page_id_returns_null_when_zero(): void
+    {
+        \Brain\Monkey\Functions\expect('get_field')
+            ->once()
+            ->with('index_town_alt', 'option')
+            ->andReturn(0);
+
+        self::assertNull(Helpers::index_town_alt_page_id());
+    }
 }