feat: many category and sub can be in playlist

app/Models/MusicSubcategory.php

@@ -4,6 +4,7 @@
 
 use Illuminate\Database\Eloquent\Model;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
+use Illuminate\Database\Eloquent\Relations\BelongsToMany;
 use Illuminate\Database\Eloquent\Relations\HasMany;
 class MusicSubcategory extends Model
 {
@@ -23,9 +24,9 @@ public function category(): BelongsTo
         return $this->belongsTo(MusicCategory::class, 'category_id');
     }
     
-    public function playlists(): HasMany
+    public function playlists(): BelongsToMany
     {
-        return $this->hasMany(MusicPlaylist::class, 'subcategory_id');
+        return $this->belongsToMany(MusicPlaylist::class, 'music_subcategory_playlist', 'subcategory_id', 'playlist_id');
     }
     
     public function image(): BelongsTo
@@ -35,7 +36,7 @@ public function image(): BelongsTo
     
     public function getActivePlaylistsAttribute()
     {
-        return $this->playlists()->where('is_active', true)->orderBy('order')->get();
+        return $this->playlists()->where('music_playlists.is_active', true)->orderBy('music_playlists.order')->get();
     }
     
     // Get total music count across all playlists in this subcategory