Introduce a feature to set a configurable limit for the maximum number of SMS parts allowed for a single message. If the message exceeds the defined limit, it should not be processed for sending. This would serve as a safeguard against accidental high-cost messages caused by excessively long texts.

Requirements:

The ability to define a custom maximum SMS part limit (e.g., via the platform or API).
Messages exceeding this limit should not be sent, with a clear error message provided to the user.
The limit should be adjustable per account or project to align with individual cost management needs.
Reasoning:
This feature would help users avoid unintentional overspending due to long messages, providing an additional layer of control and cost protection.