Add seasonal effects for Pi Day, Pride, Rain, and Storm; enhance existing styles

- Introduced new CSS and JS files for Pi Day, Pride, Rain, and Storm effects.
- Updated existing seasonal styles (e.g., Halloween, Hearts, Resurrection) to improve performance with 'contain: layout paint'.
- Enhanced animations for seasonal effects, including adjustments to keyframes and element creation logic.
- Added configuration options for new effects in the main seasonals.js file.
- Updated test-site.html to include new seasonal options in the dropdown.

Jellyfin.Plugin.Seasonals/Web/pride.js

@@ -0,0 +1,88 @@
+// 1. Read Configuration
+const config = window.SeasonalsPluginConfig?.Pride || {};
+
+const enabled = config.EnablePride !== undefined ? config.EnablePride : true;
+const elementCount = config.HeartCount || 20;
+const heartSize = config.HeartSize || 1.5;
+const colorHeader = config.ColorHeader !== undefined ? config.ColorHeader : true;
+
+let msgPrinted = false;
+
+// 2. Toggle Function
+// Hides the effect when a video player, trailer (in full width mode), dashboard, or user menu is active.
+function togglePride() {
+  const container = document.querySelector('.pride-container');
+  if (!container) return;
+
+  const videoPlayer = document.querySelector('.videoPlayerContainer');
+  const trailerPlayer = document.querySelector('.youtubePlayerContainer');
+  const isDashboard = document.body.classList.contains('dashboardDocument');
+  const hasUserMenu = document.querySelector('#app-user-menu');
+
+  if (videoPlayer || trailerPlayer || isDashboard || hasUserMenu) {
+    container.style.display = 'none';
+    if (!msgPrinted) {
+      console.log('Pride hidden');
+      msgPrinted = true;
+    }
+  } else {
+    container.style.display = 'block';
+    if (msgPrinted) {
+      console.log('Pride visible');
+      msgPrinted = false;
+    }
+  }
+}
+
+// 3. MutationObserver
+// Watches the DOM for changes so the effect can auto-hide/show.
+const observer = new MutationObserver(togglePride);
+observer.observe(document.body, {
+  childList: true,
+  subtree: true,
+  attributes: true
+});
+
+// 4. Element Creation
+// Create and append your animated elements to the container.
+function createElements() {
+  const container = document.querySelector('.pride-container') || document.createElement('div');
+
+  if (!document.querySelector('.pride-container')) {
+    container.className = 'pride-container';
+    container.setAttribute('aria-hidden', 'true');
+    document.body.appendChild(container);
+  }
+
+  if (colorHeader) {
+      const header = document.querySelector('.skinHeader');
+      if (header) {
+          header.classList.add('pride-header');
+      }
+  }
+
+  const heartEmojis = ['❤️', '🧡', '💛', '💚', '💙', '💜'];
+
+  for (let i = 0; i < elementCount; i++) {
+    const el = document.createElement('div');
+    el.className = 'pride-heart';
+    
+    el.innerText = heartEmojis[Math.floor(Math.random() * heartEmojis.length)];
+    el.style.fontSize = `${heartSize}rem`;
+    el.style.left = `${Math.random() * 100}vw`;
+    el.style.animationDuration = `${5 + Math.random() * 5}s`;
+    el.style.animationDelay = `${Math.random() * 5}s`;
+    el.style.marginLeft = `${(Math.random() - 0.5) * 100}px`;
+
+    container.appendChild(el);
+  }
+}
+
+// 5. Initialization
+function initializePride() {
+  if (!enabled) return;
+  createElements();
+  togglePride();
+}
+
+initializePride();