perf(brain): keep ollama models resident to kill voice cold-start latency

Default ollama keep_alive is 5 min, so any voice turn after a short idle paid
a full Qwen3 8B reload into the GPU (~30-60s) before replying. Set
OLLAMA_KEEP_ALIVE=-1 so the chat + embed models stay loaded.

Measured: post-idle turn ~60s -> steady-state ~4.5s per turn (model pinned
"Forever" in `ollama ps`).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

docker-compose.yml

@@ -17,6 +17,11 @@ services:
   ollama:
     image: ollama/ollama:latest
     restart: unless-stopped
+    environment:
+      # Keep the chat + embed models resident so voice turns never pay a cold
+      # reload. Default keep_alive is 5 min, so every post-idle turn took
+      # ~30-60s while Qwen3 8B reloaded into the GPU. -1 = never unload.
+      OLLAMA_KEEP_ALIVE: "-1"
     volumes:
       - ollama_models:/root/.ollama
     # GPU: needs nvidia-container-toolkit on the host (CDI). Verified on the