feat: Add cover art support and auto-migration

- Extract cover art from MP3s during upload
- Display cover art in game result screens (win/loss)
- Add coverImage field to Song model
- Add migration script to backfill covers for existing songs
- Configure Docker to run migration script on startup

app/api/songs/route.ts

@@ -21,6 +21,7 @@ export async function GET() {
         artist: song.artist,
         filename: song.filename,
         createdAt: song.createdAt,
+        coverImage: song.coverImage,
         activations: song.puzzles.length,
     }));
 
@@ -62,11 +63,30 @@ export async function POST(request: Request) {
 
         await writeFile(path.join(uploadDir, filename), buffer);
 
+        // Handle cover image
+        let coverImage = null;
+        try {
+            const metadata = await parseBuffer(buffer, file.type);
+            const picture = metadata.common.picture?.[0];
+
+            if (picture) {
+                const extension = picture.format.split('/')[1] || 'jpg';
+                const coverFilename = `cover-${Date.now()}.${extension}`;
+                const coverPath = path.join(process.cwd(), 'public/uploads/covers', coverFilename);
+
+                await writeFile(coverPath, picture.data);
+                coverImage = coverFilename;
+            }
+        } catch (e) {
+            console.error('Failed to extract cover image:', e);
+        }
+
         const song = await prisma.song.create({
             data: {
                 title,
                 artist,
                 filename,
+                coverImage,
             },
         });
 
@@ -123,6 +143,16 @@ export async function DELETE(request: Request) {
             // Continue with DB deletion even if file deletion fails
         }
 
+        // Delete cover image if exists
+        if (song.coverImage) {
+            const coverPath = path.join(process.cwd(), 'public/uploads/covers', song.coverImage);
+            try {
+                await unlink(coverPath);
+            } catch (e) {
+                console.error('Failed to delete cover image:', e);
+            }
+        }
+
         // Delete from database (will cascade delete related puzzles)
         await prisma.song.delete({
             where: { id: Number(id) },