feat(vllm,litellm): lfm2.5-2.6b non-prod bake-off alias for brokkr

vllm-lfm25 on ana-ml2 GPU1 :8021 (LiquidAI/LFM2.5-2.6B, util 0.09 into
unreserved slack, max-len 16384, no reasoning-parser so content is non-empty).
LiteLLM alias lfm2.5-2.6b with vendor sampling baked as default (temp 0.1;
top_k 50 + repetition_penalty 1.1 via extra_body). Eval-only, not in any
routing chain, pending operator ruling on LFM Open License production use.

stacks/vllm/.env.example

@@ -142,3 +142,18 @@ CODER_MAX_MODEL_LEN=8192
 CODER_KV_CACHE_DTYPE=fp8
 CODER_GPU_MEM_UTIL=0.06
 CODER_MAX_NUM_SEQS=32
+
+# LFM2.5-2.6B — NON-PRODUCTION bake-off alias vs granite (brokkr R-target 2026-08-10).
+# LiquidAI LFM Open License v1.0 (<USD 10M-rev commercial, not OSI) — eval-only pending
+# an operator production ruling. Reasoning model (emits <think>); served raw (no vLLM
+# reasoning-parser) so content is non-empty. util 0.09 (~8.6GB) fits GPU1's free slack
+# without touching production reservations; max-len 16384 keeps KV small (bake-off
+# doesn't need the 131k ceiling). Vendor sampling lives in the LiteLLM alias.
+LFM25_PORT=8021
+LFM25_GPU_ID=1
+LFM25_MODEL=LiquidAI/LFM2.5-2.6B
+LFM25_SERVED_NAME=lfm2.5-2.6b
+LFM25_MAX_MODEL_LEN=16384
+LFM25_KV_CACHE_DTYPE=auto
+LFM25_GPU_MEM_UTIL=0.09
+LFM25_MAX_NUM_SEQS=8