feat(cache): Verhaltensprobe und Smoke für WP Super Cache

SuperCacheProbe prüft beim Prüfen, ob wp_cache_post_edit die Cache-Datei einer Testseite entfernt; während der Probe ist nur der Einzelseiten-Purge erlaubt, der Pfad kommt aus home und es werden nur feste Dateinamen gelöscht. ProbeStep bündelt die Schrittlogik von Pods und WP Super Cache; ThrowawayPost hält Marker und Titel zentral und räumt auch private Probe-Seiten auf (WP Super Cache wie Pods beim Laden des Reiters). super-cache-smoke.sh prüft gegen das echte Plugin; lib.sh sperrt parallele Smoke-Läufe per flock, wp-config.php wird atomar wiederhergestellt. Doku: Host-Abhängigkeit des Einzel-Purges, WP-Cron für den Nachlauf, Komplett-Purge durch Divi beim Prüfen.

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

src/Compatibility/ProbeStep.php

@@ -0,0 +1,40 @@
+<?php
+
+declare(strict_types=1);
+
+namespace LIT\MCP\Compatibility;
+
+use Closure;
+
+defined('ABSPATH') || exit;
+
+/** The one check step a profile's behaviour probe makes (Profile::$extraSteps), shared by Pods and WP Super Cache. */
+final class ProbeStep
+{
+    /**
+     * Skipped while the manifest is red (the probe would fail anyway). A probe with nothing to probe (null) is a
+     * green step that says so, not a skipped one: a skipped step makes the report red and would lock the plugin on a
+     * site that simply has nothing to probe yet.
+     *
+     * @param Closure(): (list<string>|null) $probe Problems, [] = green, null = nothing to probe.
+     * @return Closure(bool): list<CheckStep>
+     */
+    public static function extra(string $key, string $label, string $labelNothingToProbe, Closure $probe): Closure
+    {
+        return static function (bool $manifestClean) use ($key, $label, $labelNothingToProbe, $probe): array {
+            if (! $manifestClean) {
+                return [new CheckStep($key, [], true, $label)];
+            }
+
+            $none = false;
+            $problems = CompatibilityCheck::guarded(static function () use ($probe, &$none): array {
+                $result = $probe();
+                $none = $result === null;
+
+                return $result ?? [];
+            });
+
+            return [new CheckStep($key, $problems, false, $none ? $labelNothingToProbe : $label)];
+        };
+    }
+}

src/Compatibility/ThrowawayPost.php

@@ -22,6 +22,11 @@ defined('ABSPATH') || exit;
  */
 final class ThrowawayPost
 {
+    /** Meta key and title prefix the Pods and WP Super Cache probes give their entries (the Divi write probe has its own). */
+    public const MARKER = '_lit_mcp_check_entry';
+
+    public const TITLE = '[LIT MCP Prüfung]';
+
     /** Only entries not modified for this long are orphans – a running check's entry is younger. */
     private const ORPHAN_AGE_SECONDS = 600;
 
@@ -68,14 +73,14 @@ final class ThrowawayPost
 
     /**
      * @param array<int, string>|string $postTypes
-     * @return list<int> IDs of entries a dead check left behind, deleted now. Only drafts whose title starts with
-     *     the prefix are considered.
+     * @return list<int> IDs of entries a dead check left behind, deleted now. Only drafts and private entries (a
+     *     probe may pass through private) whose title starts with the prefix are considered.
      */
     public function removeOrphans(array|string $postTypes): array
     {
         $posts = get_posts([
             'post_type' => $postTypes,
-            'post_status' => 'draft',
+            'post_status' => ['draft', 'private'],
             // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_key -- a handful of marked entries at most.
             'meta_key' => $this->marker,
             // post_modified_gmt, not post_date_gmt: an edit by the check keeps it current. A literal GMT timestamp,