feat: tools and limits settings tabs

Adds Einstellungen → LIT MCP → Tools (direct/indirect/disabled per
ability, only ExposurePolicy-allowed modes offered) and → Limits
(upload size, log retention, snapshot count), wired into Plugin.php.

Ruling Q11b (carried from task 6): overview.md notes that direct
visibility is configurable; hints in src/ that name a tool which is
direct by default but can be switched to indirect (content-get,
content-query, content-types, post-publish, media-search) now use the
neutral "lit/<name> (direkt: lit-<name>)" form so they stay correct
after an admin override. lit/guide (always direct) and the
media-preview/-download DIRECT_ONLY tools are unaffected.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01At3V6SjwbMe6eMzVGW3Hs7

src/Integrations/WordPress/PostGuard.php

@@ -88,8 +88,8 @@ final class PostGuard
                 (int) $post->ID
             ),
             [$field => 'geplanter Zeitpunkt verstrichen'],
-            'Beim Nutzer nachfragen: jetzt veröffentlichen (lit-post-publish) oder neu planen (lit/post-schedule '
-                . 'über mcp-adapter-execute-ability); danach die Änderung wiederholen.'
+            'Beim Nutzer nachfragen: jetzt veröffentlichen (lit/post-publish, direkt: lit-post-publish) oder neu '
+                . 'planen (lit/post-schedule über mcp-adapter-execute-ability); danach die Änderung wiederholen.'
         );
     }
 
@@ -107,7 +107,7 @@ final class PostGuard
         if (! is_object($object)) {
             return Errors::notFound(
                 sprintf('Inhaltstyp "%s" ist nicht verfügbar.', $name),
-                'Verfügbare Inhaltstypen über lit-content-types abrufen.'
+                'Verfügbare Inhaltstypen über lit/content-types (direkt: lit-content-types) abrufen.'
             );
         }