DocumentDelta class

Represents a partial update (delta) to a document.

Delta sync only sends changed fields instead of the entire document, reducing bandwidth usage by up to 98% for large documents.

Example:

// Instead of sending entire document:
await collection.save({
  'id': '123',
  'title': 'My Document',
  'content': '... 50KB of content ...',
  'metadata': {...},
  'done': true,  // Only this changed
});

// Send only the changed field:
await collection.update('123', {'done': true});