refactor: Shared Links als Card-Grid mit Card-Menü (wie Cronjobs)

- index.html: shared-links-list → card-grid
- dashboard.js: Cards mit card-compact, card-menu-dropdown, fa-cog statt fa-robot
- dashboard.css: 60 Zeilen shared-link-*/danger-icon CSS entfernt (nutzt card-Styles)

wwwroot/css/dashboard.css

@@ -256,66 +256,6 @@
   color: var(--text);
 }
 
-/* Shared Links */
-
-.shared-links-list {
-  display: flex;
-  flex-direction: column;
-  gap: var(--badge-spacing);
-}
-
-.shared-link-row {
-  display: flex;
-  align-items: center;
-  gap: var(--box-spacing);
-  padding: var(--box-padding);
-  background: var(--f3-bg);
-  border: var(--border-width) solid var(--f3-border);
-  border-radius: var(--border-radius);
-}
-
-.shared-link-info {
-  flex: 1;
-  min-width: 0;
-  display: flex;
-  flex-direction: column;
-  gap: calc(var(--badge-spacing) / 2);
-}
-
-.shared-link-preview {
-  white-space: nowrap;
-  overflow: hidden;
-  text-overflow: ellipsis;
-}
-
-.shared-link-preview .fa {
-  opacity: var(--semi-transparent);
-  margin-right: calc(var(--badge-spacing) / 2);
-}
-
-.shared-link-meta {
-  display: flex;
-  flex-wrap: wrap;
-  gap: var(--box-spacing);
-  opacity: var(--semi-transparent);
-  font-size: calc(var(--font-size) * 0.9);
-}
-
-.shared-link-actions {
-  display: flex;
-  gap: var(--badge-spacing);
-  flex-shrink: 0;
-}
-
-.danger-icon {
-  color: var(--dangerous);
-  opacity: var(--semi-transparent);
-}
-
-.danger-icon:hover {
-  opacity: 1;
-}
-
 /* Compact cards (no image) */
 .card-compact {
   padding: var(--box-padding);