fix: fall back to Bunny Storage for cover images

components/CourseCard.tsx

@@ -1,6 +1,7 @@
 import React from 'react';
 import { PlayCircle, Download, FileText, CheckCircle2 } from 'lucide-react';
 import { Course, SectionVariant } from '../types';
+import { CourseCoverImage } from './CourseCoverImage';
 
 interface CourseCardProps {
   course: Course;
@@ -37,8 +38,8 @@ export const CourseCard: React.FC<CourseCardProps> = ({
         onClick={() => onClick?.(course)}
         className={`relative ${aspectRatioClass} w-full overflow-hidden rounded-[8px] bg-zinc-900 shadow-xl transition-all duration-300 ease-out group-hover:scale-[1.02] group-hover:shadow-2xl group-hover:shadow-orange-500/10 group-hover:z-10 ring-0 ring-white/0 group-hover:ring-2 group-hover:ring-orange-500/40`}
       >
-        <img
-          src={course.thumbnail}
+        <CourseCoverImage
+          source={course.thumbnail}
           alt={course.title}
           loading="lazy"
           draggable={false}

components/CourseCoverImage.tsx

@@ -0,0 +1,39 @@
+import React, { useEffect, useMemo, useState } from 'react';
+
+type CourseCoverImageProps = Omit<React.ImgHTMLAttributes<HTMLImageElement>, 'src' | 'onError'> & {
+  source: string;
+  onFinalError?: () => void;
+};
+
+const fallbackCoverUrl = (source: string) => {
+  try {
+    const parsed = new URL(source, window.location.origin);
+    const filename = parsed.pathname.split('/').pop() || '';
+    if (!/^[0-9a-f]{8}-[0-9a-f-]{27}\.(?:jpg|png|webp)$/i.test(filename)) return null;
+    const apiBase = import.meta.env.VITE_API_URL || '/api/v1';
+    return `${apiBase}/courses/covers/${filename}`;
+  } catch {
+    return null;
+  }
+};
+
+export const CourseCoverImage: React.FC<CourseCoverImageProps> = ({ source, onFinalError, ...props }) => {
+  const fallbackUrl = useMemo(() => fallbackCoverUrl(source), [source]);
+  const [usingFallback, setUsingFallback] = useState(false);
+
+  useEffect(() => setUsingFallback(false), [source]);
+
+  return (
+    <img
+      {...props}
+      src={usingFallback && fallbackUrl ? fallbackUrl : source}
+      onError={() => {
+        if (!usingFallback && fallbackUrl) {
+          setUsingFallback(true);
+          return;
+        }
+        onFinalError?.();
+      }}
+    />
+  );
+};

components/Hero.tsx

@@ -2,6 +2,7 @@ import React, { useEffect, useState } from 'react';
 import { Play, Plus, Sparkles } from 'lucide-react';
 import { Course } from '../types';
 import { getCourses } from '../services/db';
+import { CourseCoverImage } from './CourseCoverImage';
 
 interface HeroProps {
   onPlay?: (course: Course) => void;
@@ -20,8 +21,8 @@ export const Hero: React.FC<HeroProps> = ({ onPlay }) => {
     <div className="relative w-full min-h-[75vh] lg:min-h-[82vh] max-h-[800px] h-auto overflow-hidden group flex flex-col justify-end pt-28 pb-12 sm:pb-16 px-6 md:px-12">
       {/* Background Image with Cinematic Gradient Overlay */}
       <div className="absolute inset-0 transition-transform duration-[20s] ease-in-out group-hover:scale-105">
-        <img 
-          src={featuredCourse.thumbnail}
+        <CourseCoverImage
+          source={featuredCourse.thumbnail}
           alt={featuredCourse.title}
           className="w-full h-full object-cover object-center"
           style={{

components/SearchModal.tsx

@@ -2,6 +2,7 @@ import React, { useState, useEffect, useRef } from 'react';
 import { Search, X, Loader2, PlayCircle, Download } from 'lucide-react';
 import { Course } from '../types';
 import { getCourses } from '../services/db';
+import { CourseCoverImage } from './CourseCoverImage';
 
 interface SearchModalProps {
   isOpen: boolean;
@@ -132,8 +133,8 @@ export const SearchModal: React.FC<SearchModalProps> = ({ isOpen, onClose, onPla
                           className="cursor-pointer group bg-zinc-900/60 rounded-[8px] p-3 border border-white/5 hover:border-orange-500/40 transition-all duration-300 shadow-xl"
                         >
                           <div className="aspect-video bg-gray-900 rounded-[8px] overflow-hidden mb-3 relative">
-                            <img 
-                              src={course.thumbnail} 
+                            <CourseCoverImage
+                              source={course.thumbnail}
                               alt={course.title} 
                               className="w-full h-full object-cover opacity-80 group-hover:opacity-100 group-hover:scale-105 transition-all duration-300 rounded-[8px]" 
                               style={{