reasoning: swap to dense Qwen3-32B-bnb-4bit for reliable tool calling

DeepSeek-R1-distill's tool_choice=auto narration bug needed a real fix,
not a workaround -- Qwen3's native tool-call format (hermes-compatible
chat template) solves it at the source instead of parsing around it.
Dense Qwen3-32B avoids the MoE arch/quantization pitfalls hit by the two
prior swap attempts (Kimi-distilled Qwen3.6 MoE, AWQ Qwen3-30B-A3B) --
same bnb-4bit path already proven working on this sm70 (V100) node.

k8s/apps/llm-serving/reasoning.yaml

@@ -12,7 +12,18 @@ spec:
   predictor:
     containers:
     - args:
-      - --model=unsloth/DeepSeek-R1-Distill-Qwen-32B-bnb-4bit
+      # DeepSeek-R1-Distill-32B retired: tool_choice="auto" (what pi sends)
+      # hit a documented vLLM/R1-family conflict -- the model narrated fake
+      # tool_calls in its <think> block instead of emitting real ones,
+      # regardless of parser. Tried swapping to a Kimi-distilled Qwen3.6
+      # MoE checkpoint and an AWQ-quantized Qwen3-30B-A3B first -- both
+      # failed on real, separate blockers (unrecognized model_type; then
+      # marlin INT4 kernels needing compute capability 80+, but worker-1's
+      # GPU is sm70/V100). Landed on dense Qwen3-32B instead: native Qwen3
+      # tool-call format (no narration bug), bnb-4bit works fine on sm70
+      # (proven by the old DeepSeek config already), and no MoE
+      # arch/quantization risk this time.
+      - --model=unsloth/Qwen3-32B-bnb-4bit
       - --served-model-name=reasoning
       - --quantization=bitsandbytes
       - --dtype=float16
@@ -23,19 +34,11 @@ spec:
       - --max-num-seqs=4
       - --enable-chunked-prefill
       - --enable-prefix-caching
-      - --reasoning-parser=deepseek_r1
-      # Without these, any client sending tool_choice="auto" (pi does, for
-      # Read/Bash/etc.) gets a 400: "auto" tool choice requires
-      # --enable-auto-tool-choice and --tool-call-parser to be set.
-      # deepseek_v3 (matching --reasoning-parser above) 400s here --
-      # "DeepSeek-V3 Tool parser could not locate tool call start/end
-      # tokens in the tokenizer" -- this checkpoint is a Qwen2.5-32B base
-      # distilled on R1 traces, so its tokenizer never got DeepSeek-V3's
-      # own special tool-call tokens registered even though it kept R1's
-      # <think> reasoning format. hermes parses tool calls from plain text
-      # patterns instead of special tokens, so it works against the
-      # underlying Qwen tokenizer regardless. Verified live: deepseek_v3
-      # 400s, hermes returns a real tool_calls response.
+      # qwen3 is vLLM's dedicated reasoning parser for this family's <think>
+      # blocks.
+      - --reasoning-parser=qwen3
+      # hermes is the documented tool-call parser for general (non-Coder)
+      # Qwen3 models -- native chat template support, not narrated text.
       - --enable-auto-tool-choice
       - --tool-call-parser=hermes
       # vLLM 0.11.0's native OffloadingConnector -- spills KV cache blocks