feat: admin settings page UI/UX pass with WordPress-native patterns

- Header: h1 + logo in a wrapping flex row, hr.wp-header-end before the tabs,
  aria-current on the active tab; own CSS/JS enqueued only on this screen.
- Verbindung: ordered "So verbindest du Claude" steps, copy button (core
  clipboard.js + wp.a11y.speak), Site-Health-style status list, German details.
- Zugriff: roles as form-table fieldset, connections with site date format,
  empty-state row, confirm on revoke; ConnectionUsage records last use via
  WP_Application_Passwords::record_application_password_usage (once a day).
- Tools: plain-language legend, counter as inline notice, groups as core
  postboxes (postbox.js toggles, per-user closed state, summary when closed),
  fixed column widths with new "Art" column, submit above and below.
- Protokoll: site-timezone times with UTC tooltip, result icons, filters with
  labels in the list table nav, retention link to Limits.
- Limits: short labels with units and descriptions; snapshot count hidden but
  preserved.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/Admin/LimitsTab.php

@@ -7,7 +7,8 @@ namespace LIT\MCP\Admin;
 use LIT\MCP\Limits;
 
 /**
- * Tab "Limits": upload/download size, log retention, snapshot count (spec §8.4).
+ * Tab "Limits": upload/download size and log retention (spec §8.4). The snapshot count is
+ * kept as a hidden field until the design system feature that uses it exists.
  * Changes apply immediately – Limits::all() always reads the current option.
  */
 final class LimitsTab implements AdminTab
@@ -41,39 +42,56 @@ final class LimitsTab implements AdminTab
     {
         $values = (new Limits())->all();
         $bounds = Limits::bounds();
-        $labels = [
-            'upload_mb' => sprintf(
-                /* translators: 1: maximum value in MB, 2: cap for Base64 transfers in MB */
-                __(
-                    'Maximale Upload-/Download-Größe (MB, höchstens %1$d; Base64-Upload/Download höchstens %2$d MB)',
-                    'wp-lit-mcp'
+        $fields = [
+            'upload_mb' => [
+                __('Maximale Dateigröße', 'wp-lit-mcp'),
+                __('MB', 'wp-lit-mcp'),
+                sprintf(
+                    /* translators: 1: maximum value in MB, 2: cap for Base64 transfers in MB */
+                    __('Höchstens %1$d MB; für Base64-Übertragungen höchstens %2$d MB.', 'wp-lit-mcp'),
+                    $bounds['upload_mb'][1],
+                    Limits::INLINE_MAX_MB
                 ),
-                $bounds['upload_mb'][1],
-                Limits::INLINE_MAX_MB
-            ),
-            'log_retention_days' => __('Protokoll aufbewahren (Tage)', 'wp-lit-mcp'),
-            'snapshot_count' => __('Anzahl Designsystem-Snapshots (ab Etappe 4)', 'wp-lit-mcp'),
+            ],
+            'log_retention_days' => [
+                __('Protokoll aufbewahren', 'wp-lit-mcp'),
+                __('Tage', 'wp-lit-mcp'),
+                __('Ältere Einträge im Protokoll werden automatisch gelöscht.', 'wp-lit-mcp'),
+            ],
         ];
 
         echo '<form method="post" action="options.php">';
         settings_fields(self::GROUP);
-        echo '<table class="form-table"><tbody>';
-        foreach ($labels as $key => $label) {
+        echo '<table class="form-table" role="presentation"><tbody>';
+        foreach ($fields as $key => [$label, $unit, $description]) {
             [$min, $max] = $bounds[$key];
             printf(
                 '<tr><th scope="row"><label for="lit-mcp-%1$s">%2$s</label></th><td>'
-                    . '<input id="lit-mcp-%1$s" type="number" min="%3$d" max="%4$d" name="%5$s[%1$s]" value="%6$d">'
-                    . '</td></tr>',
+                    . '<input id="lit-mcp-%1$s" class="small-text" type="number" min="%3$d" max="%4$d"'
+                    . ' name="%5$s[%1$s]" value="%6$d" aria-describedby="lit-mcp-%1$s-description">'
+                    . ' <span class="lit-mcp-unit">%7$s</span>'
+                    . '<p class="description" id="lit-mcp-%1$s-description">%8$s</p>',
                 esc_attr($key),
                 esc_html($label),
                 esc_attr((string) $min),
                 esc_attr((string) $max),
                 esc_attr(Limits::OPTION),
-                esc_attr((string) $values[$key])
+                esc_attr((string) $values[$key]),
+                esc_html($unit),
+                esc_html($description)
             );
+            if ($key === 'upload_mb') {
+                $this->maybeRenderUploadSizeNotice($values['upload_mb']);
+            }
+            echo '</td></tr>';
         }
         echo '</tbody></table>';
-        $this->maybeRenderUploadSizeNotice($values['upload_mb']);
+        // Design system snapshots are not available yet: no visible setting, but keep the saved value.
+        printf(
+            '<input type="hidden" name="%s[snapshot_count]" value="%d">',
+            esc_attr(Limits::OPTION),
+            (int) $values['snapshot_count']
+        );
         submit_button();
         echo '</form>';
     }
@@ -96,6 +114,6 @@ final class LimitsTab implements AdminTab
             $uploadMb,
             $serverMaxMb
         );
-        printf('<p class="description">%s</p>', esc_html($message));
+        printf('<div class="notice notice-warning inline"><p>%s</p></div>', esc_html($message));
     }
 }