Decouple gray card segment surface from card body token

semantic-tokens-components.html

@@ -19,6 +19,7 @@
       <tbody>
         <tr><td>surface-card</td><td>color-light-grey</td><td>Grundfläche der Card.</td></tr>
         <tr><td>surface-card-body</td><td>color-light-grey</td><td>Fläche im Body-Segment der Card.</td></tr>
+        <tr><td>surface-card-segment-neutral</td><td>color-light-grey</td><td>Neutrale Segmentfläche für gezielte hellgraue Card-Segmente (z. B. <code>sg-card-segment--gray</code>).</td></tr>
         <tr><td>surface-card-header-primary</td><td>color-darkblue</td><td>Primärer Header-Hintergrund.</td></tr>
         <tr><td>surface-card-header-alternative</td><td>color-darkgreen</td><td>Alternativer Header-Hintergrund.</td></tr>
         <tr><td>surface-card-header-muted</td><td>color-darkbrown</td><td>Zweite alternative Header-Fläche.</td></tr>