some progress

app/Models/Exercise.php

@@ -4,6 +4,7 @@ namespace App\Models;
 
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Support\Facades\Auth;
+use Illuminate\Support\Facades\Storage;
 
 class Exercise extends Model
 {
@@ -12,6 +13,7 @@ class Exercise extends Model
         'slug',
         'exercise_db_id',
         'gif_url',
+        'poster_image',
         'instructions',
     ];
 
@@ -66,4 +68,16 @@ class Exercise extends Model
         $alias = $this->aliases()->where('user_id', $userId)->first();
         return $alias?->name ?: $name;
     }
+
+    public function getPosterUrlAttribute(): ?string
+    {
+        $poster = (string)($this->attributes['poster_image'] ?? '');
+        if ($poster === '') {
+            return null;
+        }
+        if (preg_match('/^https?:\/\//i', $poster)) {
+            return $poster;
+        }
+        return Storage::url($poster);
+    }
 }