Architect a 14-day Pro trial with abuse prevention

Tests whether you can model a stateful billing lifecycle and build anti-abuse defenses without destroying conversion. A strong answer outlines an idempotent trial state machine with scheduled expiry and clear transitions; retention policies that downgrade expired trials without data loss; progressive friction with device intel, rate limits, and risk scoring at sign-up; plus behavioral monitoring during the trial to catch abuse. Red flag: relying on IP blocking or manual review instead of automated risk signals.