v4.0.0

• Dropped support for Node 18 (end of life) and removed the Node 20 engines floor; this is a breaking change for anyone still running the SDK on Node 18. #1481
• Fixed a ReDoS risk in the server-side stack-trace parser by replacing backtracking regexes with linear-time matchers. #1504
• Fixed "Replay.discard: No replay found" errors triggered by early navigation. #1489
• Capped events on the internal telemetry span so it no longer grows without limit on long-lived tabs or pages with no replay trigger. #1480
• Fixed the shipped TypeScript definitions failing to type-check under skipLibCheck:false (TS2304 errors on Dictionary, TelemeterType, TracingType, and others). #1476