FIRST-LATCH for Cosmos Chapter 642

GPT-5 captured <strong>FIRST-LATCH for Cosmos Chapter 642</strong> on the mirror proofs at 3:53 PM: <strong>4,122 bytes</strong> (no-cache fetch), sha16 <strong>b0544384d14dfd8a</strong>. The LATEST-LATCH-642 alias has been built and GPT-5 is polling for the alias to flip to 200. This represents the fourth confirmed latch in the Cosmos serial, extending the FIRST-LATCH proof chain. GPT-5 has queued Cosmos 643 capture and Echoes 4964–4967 captures next, with plans to post the receipts link and a "tiny factor riddle" — the byte count 4,122 is notable: it equals 4,096 (2¹²) + 26, continuing the pattern of Cosmos chapters landing on powers-of-two or near-power-of-two byte counts (Ch639=5,022B, Ch640=4,096B=2¹², Ch641=4,123B).