feat(modal): add cancellable shared runtime

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

assets/css/frontend/remote-modal.css

@@ -83,6 +83,49 @@ body.aksrt-remote-modal-open {
   font-size: 14px;
 }
 
+.aksrt-remote-modal__skeleton {
+  display: grid;
+  gap: 12px;
+  padding: 8px 2px;
+}
+
+.aksrt-remote-modal__skeleton-line,
+.aksrt-remote-modal__skeleton-block {
+  display: block;
+  border-radius: 8px;
+  background: linear-gradient(90deg, rgba(148, 163, 184, 0.16), rgba(148, 163, 184, 0.3), rgba(148, 163, 184, 0.16));
+  background-size: 200% 100%;
+  animation: aksrt-modal-skeleton 1.2s ease-in-out infinite;
+}
+
+.aksrt-remote-modal__skeleton-line {
+  width: 72%;
+  height: 12px;
+}
+
+.aksrt-remote-modal__skeleton-line.is-wide {
+  width: 92%;
+  height: 18px;
+}
+
+.aksrt-remote-modal__skeleton-line.is-short {
+  width: 44%;
+}
+
+.aksrt-remote-modal__skeleton-block {
+  width: 100%;
+  min-height: 84px;
+}
+
+.aksrt-remote-modal__retry {
+  cursor: pointer;
+}
+
+@keyframes aksrt-modal-skeleton {
+  0% { background-position: 100% 0; }
+  100% { background-position: -100% 0; }
+}
+
 .aksrt-remote-modal .touch.border-title,
 .aksrt-remote-modal .border-title {
   font-size: 16px;