feat(changelog): Hook lit_mcp_changed

ChangeLog::record() löst nach jeder erfolgreichen oder teilweise gespeicherten Änderung lit_mcp_changed(ability, objectType, objectId, logId) aus, nie bei abgelehnten. Die Werte sind gekürzt wie im Protokoll; Ausnahmen von Listenern werden protokolliert und ändern das Ergebnis des Tools nicht.

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

src/ChangeLog/ChangeLog.php

@@ -18,6 +18,9 @@ class ChangeLog
 {
     public const TABLE = 'lit_mcp_log';
 
+    /** Fires after every write that changed something (result ok or partial), see announce(). */
+    public const CHANGED_ACTION = 'lit_mcp_changed';
+
     public function __construct(private ?\wpdb $db = null)
     {
     }
@@ -42,15 +45,19 @@ class ChangeLog
         string $result = 'ok'
     ): ?int {
         $wpdb = $this->db();
+        // Shortened once: the row and the announcement carry the same values.
+        $ability = mb_substr($ability, 0, 100);
+        $objectType = mb_substr($objectType, 0, 50);
+        $objectId = mb_substr($objectId, 0, 191);
         $inserted = $wpdb->insert(
             $this->tableName(),
             [
                 'created_at' => current_time('mysql', true),
                 'user_id' => get_current_user_id(),
                 'client' => $this->sanitizedClientName(),
-                'ability' => mb_substr($ability, 0, 100),
-                'object_type' => mb_substr($objectType, 0, 50),
-                'object_id' => mb_substr($objectId, 0, 191),
+                'ability' => $ability,
+                'object_type' => $objectType,
+                'object_id' => $objectId,
                 'summary' => mb_substr($summary, 0, 500),
                 'revision_id' => $revisionId,
                 'snapshot_id' => $snapshotId,
@@ -59,12 +66,36 @@ class ChangeLog
             ['%s', '%d', '%s', '%s', '%s', '%s', '%s', '%d', '%s', '%s']
         );
 
+        $logId = null;
         if ($inserted === false) {
             Log::line(sprintf('change log insert failed for %s %s:%s', $ability, $objectType, $objectId));
-            return null;
+        } else {
+            $logId = (int) $wpdb->insert_id;
         }
 
-        return (int) $wpdb->insert_id;
+        if ($result !== 'refused') {
+            self::announce($ability, $objectType, $objectId, $logId);
+        }
+
+        return $logId;
+    }
+
+    /**
+     * do_action('lit_mcp_changed', ability, objectType, objectId, logId): a write happened (result ok or partial,
+     * never refused), even if its log row did not (logId null).
+     *
+     * ability, objectType and objectId are shortened like the log row (100/50/191 characters). objectId is an
+     * identifier or name from the tool input (post ID, option name, menu location ...): untrusted text, validate
+     * before use. A listener that throws is caught and logged, the caller must not see a failed write; exit and
+     * wp_die in a listener are not caught and end the request.
+     */
+    private static function announce(string $ability, string $objectType, string $objectId, ?int $logId): void
+    {
+        try {
+            do_action(self::CHANGED_ACTION, $ability, $objectType, $objectId, $logId);
+        } catch (\Throwable $e) {
+            Log::failure(self::CHANGED_ACTION, $e);
+        }
     }
 
     /**