fix: update media card positioning and styles

- Removed unnecessary positioning styles from media library card types.
- Added a new style for the thumbnail card type to adjust its position.
- Updated the MediaLibraryPage component to apply the new thumbnail style conditionally based on the compact view.

frontend/src/app.css

@@ -5580,8 +5580,6 @@ a.analysis-split__nav-item {
 }
 .media-library__card-type {
   position: absolute;
-  left: 6px;
-  top: 6px;
   z-index: 2;
   display: inline-flex;
   align-items: center;
@@ -5594,11 +5592,18 @@ a.analysis-split__nav-item {
   box-shadow: 0 1px 4px rgba(0, 0, 0, 0.1);
   pointer-events: none;
 }
+/* Kachel: unten links — Checkbox liegt oben links */
+.media-library__card-type--thumb-bl {
+  left: 6px;
+  bottom: 6px;
+  top: auto;
+}
 .media-library__card-type--compact {
   width: 22px;
   height: 22px;
   left: 3px;
   top: 3px;
+  bottom: auto;
   border-radius: 6px;
 }
 .media-library__card-copyright {

frontend/src/pages/MediaLibraryPage.jsx

@@ -217,7 +217,7 @@ function MediaTypeGlyph({ mimeType, compact }) {
   const sz = compact ? 12 : 14
   return (
     <span
-      className={`media-library__card-type${compact ? ' media-library__card-type--compact' : ''}`}
+      className={`media-library__card-type${compact ? ' media-library__card-type--compact' : ' media-library__card-type--thumb-bl'}`}
       title={label}
       aria-label={`Medientyp: ${label}`}
     >