fix(ui): resolve overlap between media item badges and sticky action bar

- Added z-index: 20 to .action-bar to ensure it stays above absolute-positioned badges (z-index: 10).
- Added position: relative to list items in plan and match modals to correctly contain badges.
- Ensured action bar has solid background to cover scrolling content.

src/MediaManager.html

@@ -300,6 +300,7 @@
       border-bottom-right-radius: 12px;
       display: flex;
       gap: 8px;
+      z-index: 20;
     }
 
     /* Modal */
@@ -574,6 +575,12 @@
     .unlink-btn:hover {
       background: #fee2e2;
     }
+
+    /* Ensure plan list items contain their absolute children */
+    #details-content li,
+    #match-modal-text li {
+      position: relative;
+    }
   </style>
 </head>