v3.62.0 — archive replay header sanitization

Fixes archive replay crashes when recorded response headers contain folded newline-separated values.

• Sanitizes recorded replay headers before writeHead() so newline-separated values are emitted as comma-separated header values.
• Verified against the https://www.multi-turn.ai archive case from #1: replay now returns 200 instead of crashing with ERR_INVALID_CHAR.