feat(compose): allow external Ollama via OLLAMA_BASE_URL override

For the split where the LLM runs on a separate LAN host (e.g. a GPU box at
192.168.10.9) and the app stack runs elsewhere (192.168.10.5), the brain must
reach Ollama over the network. The javis service hardcoded
OLLAMA_BASE_URL=http://ollama:11434, ignoring any .env value, so the app could
only use the in-stack Ollama. Make it ${OLLAMA_BASE_URL:-http://ollama:11434}:
default unchanged (all-in-one), overridable to point at an external Ollama.
Document the external-Ollama setup in .env.example and DEPLOY.md, refresh the
browser-host IP examples (.9→.5), and de-hardcode the .9 example in novnc.ts.

docker-compose.yml

@@ -66,8 +66,13 @@ services:
       - path: .env
         required: false
     environment:
-      # Point the brain at the ollama service and the bot at the in-container bridge.
-      OLLAMA_BASE_URL: http://ollama:11434
+      # Point the brain at Ollama. Default is the in-stack `ollama` service
+      # (all-in-one). Override OLLAMA_BASE_URL in .env to reach an EXTERNAL Ollama
+      # over the LAN (e.g. a GPU host at http://192.168.10.9:11434) — used when
+      # this stack runs on a separate machine from the LLM. When overridden, do
+      # NOT start the in-stack `ollama`/`ollama-init` services (bring the app up
+      # with `docker compose up -d javis`) and pull the models on the LLM host.
+      OLLAMA_BASE_URL: ${OLLAMA_BASE_URL:-http://ollama:11434}
       OLLAMA_CHAT_MODEL: ${OLLAMA_CHAT_MODEL:-qwen2.5:3b}
       # Auxiliary small-model calls (intent judge, tool router, arg extraction,
       # query decomposition) run on this fast model so the big chat model only
@@ -112,7 +117,7 @@ services:
       CDP_BIND: ${CDP_BIND:-127.0.0.1}
       CDP_PORT: ${CDP_PORT:-9222}
       # Where the bot drives Chrome. Loopback for full/browser; on a remote bot
-      # set CDP_HOST to the browser host's LAN IP (e.g. 192.168.10.9).
+      # set CDP_HOST to the browser host's LAN IP (e.g. 192.168.10.5).
       CDP_HOST: ${CDP_HOST:-127.0.0.1}
       # Browser-control endpoint. The browser host serves it (BIND/PORT); a
       # remote bot sets BROWSER_CONTROL_URL=http://<browser-host>:8777 so its