feat: Add AWS IAM authentication support for MySQL

- Add @aws-sdk/rds-signer dependency for RDS auth token generation
- Extend CLI arguments with --aws-iam-auth and --aws-region options
- Implement automatic AWS RDS auth token generation in MySQL adapter
- Auto-enable SSL for AWS IAM authentication (required by RDS)
- Add comprehensive error handling for AWS credential issues
- Update documentation with AWS IAM authentication examples
- Maintain backward compatibility with existing authentication methods

Resolves the need for secure AWS RDS connections without hardcoded passwords.

Author: fab0492

docs/docs/connection-reference.md

@@ -75,18 +75,29 @@ node dist/src/index.js --postgresql --host dbserver.example.com --database sampl
 | `--mysql` | Specifies MySQL mode | - | Yes |
 | `--host` | MySQL hostname or IP | - | Yes |
 | `--database` | Database name | - | Yes |
-| `--user` | MySQL username | - | No |
-| `--password` | MySQL password | - | No |
+| `--user` | MySQL username | - | No* |
+| `--password` | MySQL password | - | No* |
 | `--port` | MySQL port | 3306 | No |
 | `--ssl` | Use SSL connection (true/false or object) | false | No |
 | `--connection-timeout` | Connection timeout in ms | 30000 | No |
+| `--aws-iam-auth` | Enable AWS IAM authentication | false | No |
+| `--aws-region` | AWS region for RDS IAM auth | - | No** |
 
-### Example
+*Required for standard authentication  
+**Required when using `--aws-iam-auth`
+
+### Standard Authentication Example
 
 ```bash
 node dist/src/index.js --mysql --host localhost --database sample_db --port 3306 --user root --password secret
 ```
 
+### AWS IAM Authentication Example
+
+```bash
+node dist/src/index.js --mysql --aws-iam-auth --host rds-endpoint.region.rds.amazonaws.com --database sample_db --user aws-username --aws-region us-east-1
+```
+
 ## Environment Variables
 
 Instead of specifying sensitive credentials on the command line, you can use environment variables: