Add media carousel section to homepage

Display past event photos in an auto-playing carousel between the
"What is Spanglish?" and "Stay Updated" sections. Images are loaded
dynamically from /images/carrousel/ folder with support for jpg, png,
and webp formats.

frontend/src/lib/carouselImages.ts

@@ -0,0 +1,37 @@
+import fs from 'fs';
+import path from 'path';
+
+export interface CarouselImage {
+  src: string;
+  alt: string;
+}
+
+/**
+ * Reads all images from the carrousel folder at build/request time.
+ * Supports jpg, jpeg, png, webp, and gif formats.
+ */
+export function getCarouselImages(): CarouselImage[] {
+  const carrouselDir = path.join(process.cwd(), 'public', 'images', 'carrousel');
+  
+  try {
+    const files = fs.readdirSync(carrouselDir);
+    
+    // Filter for supported image formats
+    const supportedExtensions = ['.jpg', '.jpeg', '.png', '.webp', '.gif'];
+    const imageFiles = files.filter((file) => {
+      const ext = path.extname(file).toLowerCase();
+      return supportedExtensions.includes(ext);
+    });
+    
+    // Sort by filename (which includes date) for consistent ordering
+    imageFiles.sort();
+    
+    return imageFiles.map((file) => ({
+      src: `/images/carrousel/${file}`,
+      alt: 'Spanglish language exchange event moment',
+    }));
+  } catch (error) {
+    console.error('Error reading carrousel directory:', error);
+    return [];
+  }
+}