fix(brain): route auxiliary small-model calls to an available model

The config template never set intent_judge_model, so it fell back to the code
default gemma4:e2b. That model is not pulled by this stack (Ollama only has
qwen2.5:3b, qwen3:8b, nomic-embed-text), so every auxiliary small-model call —
intent judge, tool router, weather place extraction, query decomposition —
targeted a non-existent model, silently failed, and fell open. This crippled
tool routing and argument extraction on the 3B brain.

Render intent_judge_model from a new OLLAMA_INTENT_MODEL env var that defaults
to OLLAMA_CHAT_MODEL, so the auxiliary calls reuse the already-warm chat model
(one resident model, no extra load). tool_router_model="" then resolves through
the chain to the same model.

Verified: rendered jarvis.json now has intent_judge_model=qwen2.5:3b, and the
weather place extractor returns "서울" / "Tokyo" (it returned None for
everything while pointed at the missing gemma4:e2b).

docker/jarvis-config.template.json

@@ -4,6 +4,7 @@
   "ollama_base_url": "${OLLAMA_BASE_URL}",
   "ollama_embed_model": "${OLLAMA_EMBED_MODEL}",
   "ollama_chat_model": "${OLLAMA_CHAT_MODEL}",
+  "intent_judge_model": "${OLLAMA_INTENT_MODEL}",
   "tts_enabled": true,
   "tts_engine": "piper",
   "tts_piper_model_path": "${TTS_PIPER_MODEL_PATH}",