Git-Deploy per Tag: deploy.sh, Version aus RELEASE, Worker-Pruefung

- dev/betrieb/deploy.sh: Tag auschecken, composer, Caches leeren (bewusst
  kein route:/config:cache wegen hostabhaengiger Routen und env()-Aufrufen),
  horizon:terminate, FPM-Reload, Worker-Pruefung am Ende
- dev/betrieb/README.md: Einrichtung Server, Umstellung des Live-Verzeichnisses,
  Release, Deploy, Rollback
- config('app.version') aus RELEASE, php artisan about --only=mivita
- monitoring:queue-probe prueft nach dem Deploy, ob Horizon Jobs abholt
- Vorlage dev/git-deploy-monitoring aus Pressekonto

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/Unit/Monitoring/ReleaseTest.php

@@ -0,0 +1,38 @@
+<?php
+
+use App\Support\Monitoring\Release;
+
+/**
+ * Versionskennung: APP_VERSION vor der Datei RELEASE, die
+ * dev/betrieb/deploy.sh beim Deploy mit dem Tag beschreibt.
+ */
+beforeEach(function () {
+    $this->dir = sys_get_temp_dir().'/release-test-'.uniqid();
+    mkdir($this->dir);
+});
+
+afterEach(function () {
+    @unlink($this->dir.'/RELEASE');
+    @rmdir($this->dir);
+});
+
+test('the configured value wins over the release file', function () {
+    file_put_contents($this->dir.'/RELEASE', "v1.0.0\n");
+
+    expect(Release::current('v1.2.0', $this->dir))->toBe('v1.2.0');
+});
+
+test('the release file is used when nothing is configured', function () {
+    file_put_contents($this->dir.'/RELEASE', "v1.3.1\n");
+
+    expect(Release::current(null, $this->dir))->toBe('v1.3.1')
+        ->and(Release::current('  ', $this->dir))->toBe('v1.3.1');
+});
+
+test('without file or with garbage there is no release', function () {
+    expect(Release::current(null, $this->dir))->toBeNull();
+
+    file_put_contents($this->dir.'/RELEASE', '<git rev-parse --short HEAD>   # bei jedem Deploy');
+
+    expect(Release::current(null, $this->dir))->toBeNull();
+});