feat(reward-seat): move Skywork reward seat from fv-ml1 to esh-ml1; audit finds nothing superseding it

- Audit: Skywork-Reward-V2-Llama-3.1-8B is still #1 of 188 on AllenAI's
  RewardBench 2 per-sample results; no Skywork V3; the -40M sibling is
  vendor-marked experimental. Our AWQ W4A16 quant: 0.847 vs published bf16
  0.860 on a 150-prompt sample (within +/-2.9 pt SE), 96.2% pairwise
  agreement. Double BOS from vLLM on pre-templated text costs a further
  ~2.7 pts; callers must send add_special_tokens=false.
- No working consumer: 0 requests since 2026-09-13; Worldtree Domari points
  at a dead IP with a non-vLLM schema (reported to worldtree-dev).
- Move: sha256-identical model copy; vLLM v0.24.0 on esh-ml1 :8003 at 0.55
  util (KV 1.30x of a 16k request). Parity vs fv-ml1: 149/150 verdicts,
  99.8% pairwise signs, raw |delta| median 0.049.
- Gateway /scalar-judge passthrough -> 10.0.50.80:8003; fv-ml1 vllm-reward
  removed (~10.2 GB freed on GPU 1). stacks/vllm now holds only vllm-coder.

stacks/vllm/.env.example

@@ -14,7 +14,7 @@ VLLM_VERSION=v0.24.0
 # Host ports (container always listens on 8000 internally)
 # (EMBED_PORT 8001 / RERANK_PORT 8013 retired 2026-09-25 with their seats —
 # embedding + reranking moved to TEI on esh-ml1, stacks/embed-rerank.)
-REWARD_PORT=8003
+# REWARD_PORT=8003   (retired here 2026-09-25 — the reward seat moved to esh-ml1, stacks/reward-seat)
 
 # GPU assignment — all services share this GPU
 # (ana-ml2 has 0 and 1; default 1 keeps 0 free for heavy LLM work in llama-swap)
@@ -54,13 +54,13 @@ GPU_ID=1
 # each at 0.05 (mostly util-reservation waste); 0.03 (~3.6 GB) fits weights +
 # CUDA context with room, freeing ~4 GB back to granite. Recreate them ONE AT A
 # TIME — concurrent recreate races the memory-profiling assertion.
-REWARD_GPU_MEM_UTIL=0.10
+# REWARD_GPU_MEM_UTIL=0.10   (retired here 2026-09-25 — the reward seat moved to esh-ml1, stacks/reward-seat)
 
 # Context length caps — lower these if VRAM is tight.
 # Qwen3-Embedding supports up to 32k; reranker up to 32k.
 # Skywork capped at 16k server-side as defense-in-depth; JudgeClient also
 # enforces the cap at dispatch time per spec.
-REWARD_MAX_MODEL_LEN=16384
+# REWARD_MAX_MODEL_LEN=16384   (retired here 2026-09-25 — the reward seat moved to esh-ml1, stacks/reward-seat)
 
 # Optional API key — leave blank for no auth (fine on the internal network).
 # If set, all three services require `Authorization: Bearer <key>`.