chore(psr4): phase 1 — rename 7 top-level dirs to PascalCase

Atomic case-rename of the seven class-holding source directories to match the
PSR-4 namespace casing, plus every consequent path reference. No code logic
changes — pure structural rename. (config/content/resources/signals/migrations/
ministra/storage/tmp/vendor/www/bin stay lowercase.)

- git mv: core→Core, domain→Domain, infrastructure→Infrastructure,
  streaming→Streaming, modules→Modules, cli→Cli, public→Public (module subdirs
  like Modules/plex stay lowercase; loaded by ModuleLoader, not Composer).
- PHP filesystem paths updated across src/ + tests/: require/include, glob/scandir
  bases, view includes, asset/nginx-alias paths, autoload.php registerDirectories(),
  ModuleLoader/ModuleManager module roots, console.php discovery dirs.
- src/composer.json PSR-4 vendored-lib paths → Core/Parsing/...; vendor/ regenerated.
- nginx.conf: docroot + SCRIPT_FILENAME → Public/. SCRIPT_NAME and the public-facing
  /streaming/*.php compat routes are URLs, left unchanged.
- Build/CI: Makefile LB_DIRS / LB_DIRS_TO_REMOVE / LB_FILES_TO_REMOVE PascalCased
  (closes the LB-archive privileged-leak blocker); phpstan.dist.neon paths/
  scanDirectories/excludePaths; phpunit.xml.dist coverage; phpstan-baseline.neon
  regenerated (294→294 errors, no new resolution failures).
- migrations/deleted_files.txt: old lowercase trees listed for client cleanup
  (assumes case-sensitive FS — the supported Linux target).

Verified: grep-gate 0 live lowercase-dir require/include in src+tests; php -l clean;
PHPUnit 292/292; PHPStan no errors; Composer first / XC_Autoloader last in SPL stack;
global classes resolve from the renamed dirs.

src/Infrastructure/database/DatabaseFactory.php

@@ -0,0 +1,64 @@
+<?php
+
+/**
+ * DatabaseFactory — создание, хранение и закрытие глобального подключения к БД.
+ *
+ * Singleton-реестр: entry points вызывают set($db), потребители — get().
+ *
+ * @package XC_VM_Infrastructure_Database
+ * @author  Divarion_D <https://github.com/Divarion-D>
+ * @copyright 2025-2026 Vateron Media
+ * @link    https://github.com/Vateron-Media/XC_VM
+ * @license AGPL-3.0 https://www.gnu.org/licenses/agpl-3.0.html
+ */
+
+class DatabaseFactory {
+	/** @var DatabaseHandler|null */
+	private static $instance = null;
+
+	/**
+	 * Сохраняет экземпляр DatabaseHandler в singleton-реестре.
+	 */
+	public static function set(DatabaseHandler $db): void {
+		self::$instance = $db;
+	}
+
+	/**
+	 * Возвращает текущий DatabaseHandler.
+	 */
+	public static function get(): ?DatabaseHandler {
+		return self::$instance;
+	}
+
+	/**
+	 * Создаёт DatabaseHandler из config.ini и кладёт в global $db + singleton.
+	 */
+	public static function connect() {
+		global $db;
+
+		if (is_object($db) && method_exists($db, 'ping') && $db->ping()) {
+			self::$instance = $db;
+			return;
+		}
+
+		if (is_object($db)) {
+			$db->close_mysql();
+			$db = null;
+		}
+
+		$db = new DatabaseHandler();
+		self::$instance = $db;
+	}
+
+	/**
+	 * Закрывает глобальное подключение к БД.
+	 */
+	public static function close() {
+		global $db;
+		if (is_object($db)) {
+			$db->close_mysql();
+			$db = null;
+		}
+		self::$instance = null;
+	}
+}