Secure Rollout Message Scheduler

Problem

Given a list of stakeholder messages, where each message is represented as [recipient, sensitivity, deadline], schedule the maximum number of messages that can be sent before or on their deadlines. Only one message can be sent per time unit, and messages with the same recipient may appear multiple times. A valid schedule must send at most one message per time unit and prioritize earlier deadlines to maximize total delivered messages.

Constraints

• 1 <= len(messages) <= 10^5
• 1 <= deadline <= 10^5
• recipient is a non-empty string
• 1 <= sensitivity <= 10^9