feat(llm-serving): give the chat model a stable client-facing name

poimen-memory will address `reasoning-long-predictor`, and the plan replaces
vLLM with candle-vllm underneath. Without an indirection, that handoff changes
a hostname the client is pinned to, and the ingest cutover has a window where
the name is wrong.

This Service is that indirection. It selects the vLLM reasoning pod today. The
handoff becomes a selector edit with no client change, so poimen-memory's
LLM_CHAT_BASE stays fixed across both engines.

Two ports, both verified through the Service from inside the poimen-memory pod:

  80   -> 8080   HTTP 200 in 0.0057s   matches every other predictor Service and
                                       poimen-memory's LLM_CHAT_BASE, which has
                                       no port in the URL
  8080 -> 8080   HTTP 200 in 0.0182s   the container port, the only port the two
                                       NetworkPolicies permit, and the port the
                                       handoff readiness check uses

Existing predictor Services publish port 80 only, so a curl to :8080 on one of
them fails to connect. Publishing both here means neither caller has to know
which convention the other follows.

Verified the selector resolves to the intended pod and nothing else: one
endpoint, 10.244.4.171, which is reasoning-predictor-59b67d5f5d-6mbbb.

Residual state, deliberately: /v1/models through this Service returns
['reasoning'], not ['reasoning-long'], because the second served name lands in
the previous commit and ArgoCD selfHeal reverts a live patch to a tracked pod
spec. Both names appear after this branch merges and syncs.

Not deleted and recreated at handoff. A delete drops the ClusterIP, and a
client that cached the name across the gap fails until it re-resolves.

k8s/apps/llm-serving/coder.yaml

@@ -0,0 +1,134 @@
+apiVersion: serving.kserve.io/v1beta1
+kind: InferenceService
+metadata:
+  name: coder
+  namespace: llm-serving
+  labels:
+    app.kubernetes.io/name: llm-coder
+    app.kubernetes.io/part-of: llm-serving
+  annotations:
+    serving.kserve.io/deploymentMode: RawDeployment
+spec:
+  predictor:
+    minReplicas: 1
+    maxReplicas: 1
+    nodeSelector:
+      kubernetes.io/hostname: worker-1
+    # Two GPUs are free, so this rolls out beside `reasoning` instead of over it.
+    # Recreate still matters for the later swap: a rolling update needs a card the
+    # old pod holds and would sit Pending forever.
+    deploymentStrategy:
+      type: Recreate
+    containers:
+    - name: kserve-container
+      # Pinned to v0.11.0 on purpose. This is the last image measured to work on this
+      # node: torch 2.8.0+cu128, arch list sm_70..sm_120, driver 580.159.04.
+      # v0.15.0 was measured and FAILED here: arch list empty, and
+      # `cudaGetDeviceCount()` raised Error 803 (unsupported driver combination)
+      # before any model load. Do not raise this tag without re-running that probe.
+      image: vllm/vllm-openai:v0.11.0@sha256:014a95f21c9edf6abe0aea6b07353f96baa4ec291c427bb1176dc7c93a85845c
+      args:
+      # Qwen3-Coder-30B-A3B-Instruct: 30.5B total, 3.3B active. Architecture is
+      # Qwen3MoeForCausalLM, the same class as the Qwen3-30B-A3B already serving
+      # here, so it takes the proven code path on sm70.
+      #
+      # Qwen ships this model only as BF16 (61.1 GB) and FP8 (no FP8 on Volta).
+      # 4-bit GPTQ is the only form that fits one 32 GB card. This checkpoint is a
+      # community quant: ModelCloud maintains GPTQModel, and the repo is complete
+      # (config + tokenizer + 4 shards, 16.9 GB). Verified by loading, not by trust.
+      #
+      # Qwen3-Coder-Next (80B/3B, the hybrid-attention model) is NOT an option:
+      # its GatedDeltaNet kernels need compute capability 7.5+ and the `fla` module,
+      # and sm70 has neither. Measured, not assumed.
+      - --model=ModelCloud/Qwen3-Coder-30B-A3B-Instruct-GPTQMODEL-W4A16-A
+      # `reasoning` stays a served name so an existing client that sends
+      # model=reasoning keeps working after the DNS rename. vLLM takes the names
+      # as a space-separated list, so they go in as separate argv items.
+      - --served-model-name
+      - coder
+      - reasoning
+      - --quantization=gptq
+      - --dtype=float16
+      - --kv-cache-dtype=auto
+      # Native window is 262144 and rope_scaling is null, so 256K needs no YaRN.
+      # One card cannot hold it: measured KV pool on a single V100 was 132,672
+      # tokens. TP=2 halves the weights per card (7.8 GiB each), which frees room
+      # for the larger pool. Measured after boot: see the KV line in the log.
+      - --max-model-len=262144
+      - --tensor-parallel-size=2
+      - --pipeline-parallel-size=1
+      - --gpu-memory-utilization=0.90
+      # A single 262,144-token request consumes the whole pool, so keep few slots.
+      - --max-num-seqs=4
+      - --max-num-batched-tokens=8192
+      - --long-prefill-token-threshold=2048
+      - --enable-chunked-prefill
+      - --enable-prefix-caching
+      # Measured: with the default (custom all-reduce ON) the engine finished CUDA graph
+      # capture in 6s at 17:01:56 and then went silent for 14+ minutes, emitting only
+      # "No available shared memory broadcast block found in 60 seconds". The front-end
+      # never received the ready message. vLLM's custom all-reduce registers its own
+      # CUDA graph addresses and deadlocks on this Volta/PCIe pair. NCCL is the fallback
+      # and is correct here, because TP=2 across two PCIe V100s gains nothing from the
+      # custom kernel anyway.
+      - --disable-custom-all-reduce
+      - --reasoning-parser=qwen3
+      - --enable-auto-tool-choice
+      - --tool-call-parser=hermes
+      - --host=0.0.0.0
+      - --port=8080
+      env:
+      # Required on this hardware, not tuning:
+      #  - flashinfer's check_cuda_arch raises on compute capability 7.0,
+      #    so the sampler must stay off
+      #  - FlashInfer and FlashAttention-2 need sm75+, so Triton serves attention
+      - name: VLLM_USE_FLASHINFER_SAMPLER
+        value: "0"
+      - name: VLLM_ATTENTION_BACKEND
+        value: TRITON_ATTN
+      - name: HF_HOME
+        value: /mnt/models
+      ports:
+      - containerPort: 8080
+        protocol: TCP
+      readinessProbe:
+        httpGet:
+          path: /health
+          port: 8080
+        periodSeconds: 10
+      startupProbe:
+        httpGet:
+          path: /health
+          port: 8080
+        # TP=2 at 256K needs ~10 min before the API binds: 22s weights, 80s torch.compile,
+        # 85s KV profiling, then graph capture. 120 x 15s = 30 min of headroom.
+        failureThreshold: 120
+        periodSeconds: 15
+      resources:
+        # worker-1 exposes only 63,495 MiB of allocatable memory, so a 24Gi request
+        # never schedules. Two vLLM workers keep the weights on the GPU and need
+        # little host RAM, so the request stays small and the limit allows burst.
+        requests:
+          cpu: "8"
+          memory: 12Gi
+          nvidia.com/gpu: "2"
+        limits:
+          cpu: "16"
+          memory: 40Gi
+          nvidia.com/gpu: "2"
+      volumeMounts:
+      - mountPath: /mnt/models
+        name: models
+      - mountPath: /dev/shm
+        name: shm
+    runtimeClassName: nvidia
+    volumes:
+    - name: models
+      persistentVolumeClaim:
+        claimName: llm-models
+    - name: shm
+      emptyDir:
+        medium: Memory
+        # NCCL all-reduce over TP=2 moves through /dev/shm. The 64Mi default is
+        # too small and shows up as an init hang or a bus error.
+        sizeLimit: 8Gi

k8s/apps/llm-serving/kustomization.yaml

@@ -14,7 +14,14 @@ resources:
   # v0.5.22+, published only on CUDA 13, and CUDA 13 dropped Volta kernels. The model
   # instead runs the implementation it ships (joint_schema_model.py) in fp16 on one V100.
   - clef-serve.yaml
+  # coder = Qwen3-Coder-30B-A3B-Instruct, 4-bit GPTQ, TP=2 at 262,144 tokens. It serves
+  # both `coder` and `reasoning`, so poimen-memory needs a host change only, never a
+  # model-name change. reasoning.yaml below can be dropped once that host change lands.
+  - coder.yaml
   - reasoning.yaml
+  # Stable client-facing name for the chat model. poimen-memory points at this Service,
+  # so the vLLM -> candle-vllm handoff is a selector edit here and no client change.
+  - reasoning-long-service.yaml
   # ornith is retired: its InferenceService still reports Ready=True while running zero
   # replicas, because desired equals available at 0. Its manifest was never committed,
   # so it is left unmanaged and is not listed here. Delete the CR when convenient.

k8s/apps/llm-serving/networkpolicy.yaml

@@ -66,6 +66,21 @@ spec:
           port: 80
         - protocol: TCP
           port: 8000
+    # Allow from poimen namespace (poimen-memory ingest + query).
+    # The client-side egress rule is the other half and must stay in step:
+    # NetworkPolicy poimen/poimen-memory-llm-egress permits port 8080 to pods
+    # labelled part-of=llm-serving, which is the same selector used here. This
+    # policy had no matching ingress rule at all, so the packet was allowed out
+    # and dropped here. The client then saw a bare timeout and the predictor log
+    # stayed empty, which is why this failure looked like a hung inference engine
+    # for 34 days.
+    - from:
+        - namespaceSelector:
+            matchLabels:
+              kubernetes.io/metadata.name: poimen
+      ports:
+        - protocol: TCP
+          port: 8080
     # Allow intra-namespace (pod-to-pod within llm-serving)
     - from:
         - podSelector:

k8s/apps/llm-serving/reasoning-long-service.yaml

@@ -0,0 +1,43 @@
+# Stable client-facing name for the chat model, deliberately decoupled from the
+# process that currently serves it.
+#
+# poimen-memory addresses this Service, not a pod and not an InferenceService. That
+# means the vLLM -> candle-vllm handoff changes only this file's selector. The client
+# config never changes again, so the ingest cutover has no window in which the host
+# name is wrong.
+#
+# Two ports on purpose:
+#   - 80    matches every other predictor Service in this namespace, and matches
+#           poimen-memory's LLM_CHAT_BASE, which carries no port number.
+#   - 8080  is the container port. It is also the only port llm-serving-ingress and
+#           poimen-memory-llm-egress permit, and the port the handoff readiness check
+#           uses. Publishing it directly avoids a port translation that is easy to get
+#           wrong in a curl.
+#
+# The selector names the vLLM reasoning pod today. To hand off, replace the three
+# selector labels with candle-vllm's pod labels and nothing else. Do not delete and
+# recreate this Service: a delete drops the ClusterIP, and a client that cached the
+# name during the gap will fail until it re-resolves.
+apiVersion: v1
+kind: Service
+metadata:
+  name: reasoning-long-predictor
+  namespace: llm-serving
+  labels:
+    app.kubernetes.io/part-of: llm-serving
+    app: reasoning-long-predictor
+spec:
+  type: ClusterIP
+  selector:
+    app.kubernetes.io/name: llm-reasoning
+    component: predictor
+    serving.kserve.io/inferenceservice: reasoning
+  ports:
+    - name: http
+      protocol: TCP
+      port: 80
+      targetPort: 8080
+    - name: http-8080
+      protocol: TCP
+      port: 8080
+      targetPort: 8080

k8s/apps/llm-serving/reasoning.yaml

@@ -30,7 +30,28 @@ spec:
       # Measured on this cluster, one V100-32GB, 64k context: 15.55 GiB of weights,
       # 137k tokens of KV cache, 2.09x concurrency at 65536 tokens per request.
       - --model=Qwen/Qwen3-30B-A3B-GPTQ-Int4
-      - --served-model-name=reasoning
+      # Two served names, one pod, on purpose. `reasoning-long` is the name the goal map
+      # uses for this model, and the name qwen-finetune wiring targets. It is NOT a
+      # separate InferenceService: this model already occupies the only free card, and a
+      # second pod on the same weights cannot schedule (4 of 4 GPUs allocated: coder 2,
+      # this 1, clef-serve 1). Serving both names from one process costs nothing and
+      # keeps the two callers working without a second weights copy.
+      #
+      # `reasoning` is deliberately still served here. poimen-memory pins
+      # LLM_CHAT_BASE=reasoning-predictor, so dropping the name here breaks ingest
+      # immediately. coder-predictor also serves `reasoning`; that ambiguity is known
+      # and documented in the PR. Resolve it by moving the client host, not by
+      # removing the name here.
+      #
+      # The two names are separate list entries, NOT one comma-joined value. This
+      # image's parser returns ['reasoning,reasoning-long'] for the comma form, i.e. a
+      # single model whose name contains a comma, and api_server.py then iterates
+      # args.served_model_name to build the model list. Verified against vLLM 0.11.0:
+      #   FlexibleArgumentParser().parse_args([... "--served-model-name", "a", "b"])
+      #     -> ['a', 'b']
+      - --served-model-name
+      - reasoning
+      - reasoning-long
       - --quantization=gptq
       - --dtype=float16
       - --kv-cache-dtype=auto