fix(core,streaming): preserve execution permissions for core scripts and redis self-healing on boot

Port of Rosmi720/XC_VM@0d39e9bd. A mode-dropping deploy could leave core
scripts non-executable and a php-fpm pool config missing, and an undefined HOST
constant broke the unique-header cookie domain:

- StartupCommand restores the executable bit on service/update/redis-server/
  daemons.sh and regenerates any missing php-fpm pool config (1..4.conf) from
  the template on boot.
- StreamAuthMiddleware derives the cookie domain through a HOST-guarded helper,
  so an undefined/empty host or a bare IP yields no domain instead of throwing
  or emitting a broken "." domain.

Adapted to this tree: the added boot blocks were split into covered helpers
(ensureExecutableScripts / ensurePhpFpmPoolConfigs / uniqueHeaderDomain) with
unit tests to stay within the complexity ceiling, the sudo chown now runs only
as root, and comments were translated to English.

tests/Unit/StreamAuthMiddlewareHostTest.php

@@ -0,0 +1,40 @@
+<?php
+
+use PHPUnit\Framework\TestCase;
+use XcVm\Streaming\Auth\StreamAuthMiddleware;
+
+/**
+ * Coverage for StreamAuthMiddleware::uniqueHeaderDomain — the HOST-guarded
+ * cookie-domain resolver. It must yield a dotted domain for a host name, and
+ * null for an undefined/empty host or a bare IP (a dot-prefixed IP is not a
+ * valid cookie domain and previously produced a broken "." domain).
+ */
+final class StreamAuthMiddlewareHostTest extends TestCase {
+
+	private function domain(): ?string {
+		$rM = new ReflectionMethod(StreamAuthMiddleware::class, 'uniqueHeaderDomain');
+		$rM->setAccessible(true);
+		return $rM->invoke(null);
+	}
+
+	protected function setUp(): void {
+		if (defined('HOST')) {
+			$this->markTestSkipped('HOST constant already defined; $_SERVER path not reachable');
+		}
+	}
+
+	public function testHostNameYieldsDottedDomain(): void {
+		$_SERVER['HTTP_HOST'] = 'cdn.example.com';
+		$this->assertSame('.cdn.example.com', $this->domain());
+	}
+
+	public function testBareIpYieldsNull(): void {
+		$_SERVER['HTTP_HOST'] = '203.0.113.9';
+		$this->assertNull($this->domain());
+	}
+
+	public function testEmptyHostYieldsNull(): void {
+		$_SERVER['HTTP_HOST'] = '';
+		$this->assertNull($this->domain());
+	}
+}