DynamoDB JSON Converter

Converts between plain JSON and DynamoDB's AttributeValue-wrapped JSON (the {"S": "..."}/{"N": "..."} format the low-level DynamoDB API and aws dynamodb CLI commands use). Covers String/Number/Boolean/Null/List/Map — the same mapping the AWS SDK's DynamoDB.Converter uses. Set types (SS/NS/BS) and binary (B) aren't produced or accepted, since plain JSON has no equivalent concept for sets or binary data.

• Plain JSON → DynamoDB JSON
• DynamoDB JSON → Plain JSON