codex preview slots

Nine fixed slots, each proxied to a local port. A slot with nothing listening returns 502.

• p1.codex.letsharkness.com → :3901
• p2 → :3902
• p3 → :3903
• p4 → :3904
• p5 → :3905
• p6 → :3906
• p7 → :3907
• p8 → :3908
• p9 → :3909

Previews are public, unindexed, and hold no real data. Promotion to a real subdomain goes through the house pipeline.