t_d7f8cd65 — astro-orbiter is a single serial llama-swap process; Hindsight's default LLM_MAX_CONCURRENT=32 burst N parallel retains -> node rejects/times out extras -> 502. Cap global + retain concurrency to 1 (native semaphore config, no code change). Raise client timeout 120->600s and ingress proxy-read/send 300->600s so a single long retain (~90s under load) survives.