feat(vllm): replace phi4-mini with Granite 4.1 8B summarizer + retune GPU 1

Granite 4.1 8B beat phi4-mini on precision in brokkr's R15 P03 eval, so it's
the new production summarizer/dreamer for nevermore.

- vllm-phi4 -> vllm-granite: official IBM FP8 (ibm-granite/granite-4.1-8b-fp8,
  compressed-tensors), GPU 1, 50K ctx, FP8-KV, CUDA graphs. Same :8004 slot.
- GPU 1 retune: the embed/rerank/reward trio was over-provisioned (embed ran a
  5.89x KV pool, reward 3.90x). Trimmed utils 0.20/0.20/0.30 -> 0.07/0.07/0.18,
  freeing ~10 GB so granite runs with CUDA graphs (not --enforce-eager) and
  keeps ~10 GB free as a hedge for future Granite text-LoRAs (--enable-lora).
- LiteLLM: phi4-mini model_list entry -> granite-4.1-8b (hosted_vllm @ :8004);
  explicit entry shadows the '*' wildcard's llama-swap route.
- nevermore repointed (LLAMA_SWAP_MODEL=granite-4.1-8b via the gateway) live.

Verified end-to-end: vLLM :8004 generates, gateway routes (gateway-granite-ok),
KV 86,768 tokens/1.69x at 50K, 0 restarts, GPU 1 10.3 GB free.

stacks/vllm/compose.yaml

@@ -201,13 +201,13 @@ services:
   # llama-swap granite-4-small pin. Generative chat model (OpenAI
   # /v1/chat/completions), so NO --runner pooling. FP8 on RTX 6000 Ada
   # (cc 8.9): near-lossless, ~1.2x, ~6 GB.
-  vllm-phi4:
+  vllm-granite:
     image: vllm/vllm-openai:${VLLM_VERSION}
-    container_name: vllm-phi4
+    container_name: vllm-granite
     restart: unless-stopped
     ipc: host
     ports:
-      - "${PHI4_PORT}:8000"
+      - "${GRANITE_PORT}:8000"
     volumes:
       - /tank/aimodels/huggingface:/hfcache
     environment:
@@ -216,34 +216,40 @@ services:
       - HUGGING_FACE_HUB_TOKEN=${HF_TOKEN:-}
       - VLLM_API_KEY=${API_KEY:-}
     command:
-      # Default = vLLM-native dynamic FP8 from the official BF16 weights (most
-      # robust on Ada). Alt = pre-quantized checkpoint: PHI4_MODEL=
-      # pytorch/Phi-4-mini-instruct-FP8 + PHI4_QUANT=torchao (see .env/README).
-      - ${PHI4_MODEL}
+      # Production summarizer (replaced phi4-mini 2026-06-05). Default = official
+      # IBM pre-quantized FP8 (compressed-tensors), loaded directly; FP8 is native
+      # on the RTX 6000 Ada (cc 8.9). Fallback to vLLM-native dynamic FP8 from
+      # BF16: GRANITE_MODEL=ibm-granite/granite-4.1-8b + GRANITE_QUANT=fp8.
+      - ${GRANITE_MODEL}
       - --served-model-name
-      - ${PHI4_SERVED_NAME}
+      - ${GRANITE_SERVED_NAME}
       - --quantization
-      - ${PHI4_QUANT}
+      - ${GRANITE_QUANT}
       - --host
       - 0.0.0.0
       - --port
       - "8000"
       - --gpu-memory-utilization
-      - ${PHI4_GPU_MEM_UTIL}
+      - ${GRANITE_GPU_MEM_UTIL}
       - --max-model-len
-      - ${PHI4_MAX_MODEL_LEN}
+      - ${GRANITE_MAX_MODEL_LEN}
       - --dtype
       - auto
-      # FP8 KV cache — halves KV memory at 128K ctx on Ada (cc 8.9); near-lossless.
+      # CUDA graphs ENABLED (no --enforce-eager) for decode throughput. Made
+      # room 2026-06-05 by right-sizing the embed/rerank/reward trio's KV pools
+      # (they were over-provisioned at 5.9x/2.0x/3.9x concurrency); GPU 1 now has
+      # ~17 GB free after granite, so graph-capture buffers fit. If the trio
+      # ever grows back, granite may need --enforce-eager again on this card.
+      # FP8 KV cache — halves KV memory; near-lossless on Ada (cc 8.9).
       - --kv-cache-dtype
-      - ${PHI4_KV_CACHE_DTYPE}
+      - ${GRANITE_KV_CACHE_DTYPE}
     deploy:
       resources:
         reservations:
           devices:
             - driver: nvidia
               device_ids:
-                - "${PHI4_GPU_ID}"
+                - "${GRANITE_GPU_ID}"
               capabilities:
                 - gpu
     healthcheck:
@@ -256,10 +262,10 @@ services:
       - tnet
     labels:
       - homepage.group=AI Systems
-      - homepage.name=vLLM Phi-4-mini (summarizer/dreamer)
+      - homepage.name=vLLM Granite 4.1 8B (summarizer)
       - homepage.icon=mdi-text-box-outline
-      - homepage.description=Phi-4-mini FP8 via vLLM (ana-ml2)
-      - homepage.href=http://10.250.50.54:${PHI4_PORT}/docs
+      - homepage.description=Granite 4.1 8B FP8 via vLLM (ana-ml2)
+      - homepage.href=http://10.250.50.54:${GRANITE_PORT}/docs
 
 networks:
   tnet: