Create a new text message record. Optionally send the SMS by setting send: true.

Default behavior (send: false or omitted):

• Creates a record in the CRM without sending
• Use this to log SMS messages sent through external systems

Sending SMS (send: true):

• Uses team's default provider if smsProviderId is not specified
• Optionally specify smsProviderId to use a specific provider
• Actually sends the SMS through the specified/default provider
• Provider must be configured and accessible to the API token

Auto-fill behavior:

• If toNumber is blank/omitted, uses the person's primary phone number (or returns error if none exists)
• If fromNumber is blank/omitted, uses the default SMS provider's phone number (or returns error if no provider configured)
• This allows simplified message creation when using default contact information