Add Eid feature: create CSS and JS for Eid symbols and animations

Jellyfin.Plugin.Seasonals/Web/eid.css

@@ -0,0 +1,53 @@
+.eid-container {
+    display: block;
+    position: fixed;
+    top: 0;
+    left: 0;
+    width: 100%;
+    height: 100%;
+    pointer-events: none;
+    z-index: 10;
+    contain: strict;
+    overflow: hidden;
+}
+
+.eid-symbol {
+    position: absolute;
+    user-select: none;
+    font-size: 1.5em;
+}
+
+.eid-symbol.floating-star {
+    opacity: 0;
+    animation: eid-twinkle 4s ease-in-out infinite;
+    mix-blend-mode: screen;
+}
+
+.lantern-rope {
+    position: absolute;
+    top: 0;
+    width: 2px;
+    background: linear-gradient(to bottom, rgba(255, 215, 0, 0.1), rgba(255, 215, 0, 0.6));
+    transform-origin: top center;
+    animation: lantern-swing 4s ease-in-out infinite alternate;
+}
+
+.lantern-emoji {
+    position: absolute;
+    bottom: -20px;
+    left: 50%;
+    transform: translateX(-50%);
+    font-size: 2.5em;
+    filter: drop-shadow(0 0 10px rgba(255, 215, 0, 0.5));
+}
+
+@keyframes lantern-swing {
+    0% { transform: rotate(-8deg); }
+    100% { transform: rotate(8deg); }
+}
+
+@keyframes eid-twinkle {
+    0% { transform: scale(0.8); opacity: 0; text-shadow: 0 0 5px gold; }
+    50% { transform: scale(1.2); opacity: 0.8; text-shadow: 0 0 20px gold; }
+    100% { transform: scale(0.8); opacity: 0; text-shadow: 0 0 5px gold; }
+}