feat(main): add Yandex Metrika tracking pixel support

README.md

@@ -59,6 +59,7 @@ The project uses several custom `$settings` in `settings.php`:
 | `telegram_secret_token` | Secret token for Telegram webhook verification |
 | `telegram_chat_id` | Telegram chat ID for moderation notifications |
 | `app_foresight` | (default: `TRUE`) Allows to disable the ForesightJS prefetch library for an environment. Only active for anonymous users. When disabled, no link prefetching is performed. |
+| `app_yandex_metrika_id` | Yandex.Metrika counter ID. When set, adds a tracking pixel (`<img src="https://mc.yandex.ru/watch/{ID}" …>`) to the bottom of every page. |
 
 ## 🧬 Quality Tools
 

app/modules/main/src/Hook/Core/YandexMetrikaPageBottom.php

@@ -0,0 +1,30 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\app_main\Hook\Core;
+
+use Drupal\Core\Hook\Attribute\Hook;
+use Drupal\Core\Site\Settings;
+
+#[Hook('page_bottom')]
+final readonly class YandexMetrikaPageBottom {
+
+  public function __invoke(array &$page_bottom): void {
+    $metrika_id = Settings::get('app_yandex_metrika_id');
+    if (!\is_string($metrika_id) || $metrika_id === '') {
+      return;
+    }
+
+    $page_bottom['app_main_yandex_metrika'] = [
+      '#type' => 'html_tag',
+      '#tag' => 'img',
+      '#attributes' => [
+        'src' => 'https://mc.yandex.ru/watch/' . \rawurlencode($metrika_id),
+        'style' => 'position:absolute; left:-9999px;',
+        'alt' => '',
+      ],
+    ];
+  }
+
+}

app/modules/main/tests/src/Unit/Hook/Core/YandexMetrikaPageBottomTest.php

@@ -0,0 +1,74 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Drupal\Tests\app_main\Unit\Hook\Core;
+
+use Drupal\app_main\Hook\Core\YandexMetrikaPageBottom;
+use Drupal\Core\Site\Settings;
+use Drupal\Tests\UnitTestCase;
+use PHPUnit\Framework\Attributes\CoversClass;
+
+#[CoversClass(YandexMetrikaPageBottom::class)]
+final class YandexMetrikaPageBottomTest extends UnitTestCase {
+
+  protected function setUp(): void {
+    parent::setUp();
+    new Settings([]);
+  }
+
+  public function testNoIdAddsNothing(): void {
+    $hook = new YandexMetrikaPageBottom();
+    $page_bottom = [];
+
+    $hook($page_bottom);
+
+    self::assertEmpty($page_bottom);
+  }
+
+  public function testEmptyStringAddsNothing(): void {
+    new Settings(['app_yandex_metrika_id' => '']);
+    $hook = new YandexMetrikaPageBottom();
+    $page_bottom = [];
+
+    $hook($page_bottom);
+
+    self::assertEmpty($page_bottom);
+  }
+
+  public function testNonStringAddsNothing(): void {
+    new Settings(['app_yandex_metrika_id' => 123]);
+    $hook = new YandexMetrikaPageBottom();
+    $page_bottom = [];
+
+    $hook($page_bottom);
+
+    self::assertEmpty($page_bottom);
+  }
+
+  public function testValidIdAddsImage(): void {
+    new Settings(['app_yandex_metrika_id' => '48390929']);
+    $hook = new YandexMetrikaPageBottom();
+    $page_bottom = [];
+
+    $hook($page_bottom);
+
+    self::assertArrayHasKey('app_main_yandex_metrika', $page_bottom);
+    self::assertSame('html_tag', $page_bottom['app_main_yandex_metrika']['#type']);
+    self::assertSame('img', $page_bottom['app_main_yandex_metrika']['#tag']);
+    self::assertSame('https://mc.yandex.ru/watch/48390929', $page_bottom['app_main_yandex_metrika']['#attributes']['src']);
+    self::assertSame('position:absolute; left:-9999px;', $page_bottom['app_main_yandex_metrika']['#attributes']['style']);
+    self::assertSame('', $page_bottom['app_main_yandex_metrika']['#attributes']['alt']);
+  }
+
+  public function testIdIsEncoded(): void {
+    new Settings(['app_yandex_metrika_id' => '48<39>09']);
+    $hook = new YandexMetrikaPageBottom();
+    $page_bottom = [];
+
+    $hook($page_bottom);
+
+    self::assertSame('https://mc.yandex.ru/watch/48%3C39%3E09', $page_bottom['app_main_yandex_metrika']['#attributes']['src']);
+  }
+
+}

assets/scaffold/local.settings.php

@@ -55,5 +55,6 @@
 $settings['telegram_chat_id'] = NULL;
 $settings['telegram_secret_token'] = NULL;
 $settings['app_foresight'] = FALSE;
+$settings['app_yandex_metrika_id'] = NULL;
 
 $config['cache_pilot.settings']['connection_dsn'] = 'tcp://php:9000';

config/cspell/dictionary.txt

@@ -37,3 +37,5 @@ TYPEHINT
 Webmozart
 wght
 youtu
+metrika
+Metrika