feat: Enhance Adventure and Collection Management

- Added support for multiple collections in AdventureSerializer, allowing adventures to be linked to multiple collections.
- Implemented validation to ensure collections belong to the current user during adventure creation and updates.
- Introduced a signal to update adventure publicity based on the public status of linked collections.
- Updated file permission checks to consider multiple collections when determining access rights.
- Modified AdventureImageViewSet and AttachmentViewSet to check access against collections instead of a single collection.
- Enhanced AdventureViewSet to support filtering and sorting adventures based on collections.
- Updated frontend components to manage collections more effectively, including linking and unlinking adventures from collections.
- Adjusted API endpoints and data structures to accommodate the new collections feature.
- Improved user experience with appropriate notifications for collection actions.

backend/server/adventures/migrations/0035_remove_adventure_collection_adventure_collections.py

@@ -0,0 +1,59 @@
+# Generated by Django 5.2.1 on 2025-06-10 03:04
+
+from django.db import migrations, models
+
+
+def migrate_collection_relationships(apps, schema_editor):
+    """
+    Migrate existing ForeignKey relationships to ManyToMany relationships
+    """
+    Adventure = apps.get_model('adventures', 'Adventure')
+    
+    # Get all adventures that have a collection assigned
+    adventures_with_collections = Adventure.objects.filter(collection__isnull=False)
+    
+    for adventure in adventures_with_collections:
+        # Add the existing collection to the new many-to-many field
+        adventure.collections.add(adventure.collection_id)
+
+
+def reverse_migrate_collection_relationships(apps, schema_editor):
+    """
+    Reverse migration - convert first collection back to ForeignKey
+    Note: This will only preserve the first collection if an adventure has multiple
+    """
+    Adventure = apps.get_model('adventures', 'Adventure')
+    
+    for adventure in Adventure.objects.all():
+        first_collection = adventure.collections.first()
+        if first_collection:
+            adventure.collection = first_collection
+            adventure.save()
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('adventures', '0034_remove_adventureimage_unique_immich_id_per_user'),
+    ]
+
+    operations = [
+        # First, add the new ManyToMany field
+        migrations.AddField(
+            model_name='adventure',
+            name='collections',
+            field=models.ManyToManyField(blank=True, related_name='adventures', to='adventures.collection'),
+        ),
+        
+        # Migrate existing data from old field to new field
+        migrations.RunPython(
+            migrate_collection_relationships,
+            reverse_migrate_collection_relationships
+        ),
+        
+        # Finally, remove the old ForeignKey field
+        migrations.RemoveField(
+            model_name='adventure',
+            name='collection',
+        ),
+    ]