feat(deploy): add brain/app roles for GPU-split deployment

Run the GPU-heavy compute (Whisper STT, Ollama LLM, TTS) on a dedicated
brain host and the bot + browser on a separate no-GPU app host, talking
over the LAN.

- supervisord: new `brain` role (bridge only) and `app` role (bot +
  desktop/Chrome, no local bridge); `full`/`browser`/`bot` unchanged.
- compose: make BRIDGE_URL overridable (was hardcoded to loopback, which
  prevented the bot from reaching a remote bridge).
- docs: DEPLOY.md "GPU split" layout with per-host .env blocks; document
  the new roles in run-if-role.sh and .env.example.

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

docs/DEPLOY.md

@@ -79,6 +79,54 @@ On the LLM host, make Ollama listen on the LAN (`OLLAMA_HOST=0.0.0.0:11434`) and
 pull the models there (`ollama pull <chat>`, `<intent>`, `<embed>`). The compose
 respects `OLLAMA_BASE_URL`, defaulting to the in-stack `ollama` service when unset.
 
+## C. GPU split: brain host (.9, GPU) + app host (.5, no GPU)
+
+All the GPU-heavy compute (Whisper STT, the Ollama LLM, and TTS) runs on the
+**brain host** (a GPU box, e.g. `192.168.10.9`). The **app host** (no GPU, e.g.
+`192.168.10.5`) runs the Discord bot and the on-screen browser, and offloads
+every STT/LLM/TTS call to the brain over the LAN.
+
+Flow: the bot (app host) POSTs captured voice to the brain's bridge; the brain
+runs STT -> LLM -> TTS on the GPU and returns the reply audio; when the LLM
+drives the browser, the brain's `controlBrowser` tool POSTs to the app host's
+control-server (port 8777), so Chrome moves on the app host's screen.
+
+### Brain host (.9 — GPU: STT + LLM + TTS)
+
+```
+# .env
+JARVIS_ROLE=brain
+BRIDGE_HOST=0.0.0.0                            # bridge listens on the LAN
+SETTINGS_PUBLISH_BIND=0.0.0.0                  # publish bridge port 8765 to the LAN
+OLLAMA_BASE_URL=http://192.168.10.9:11434      # Ollama on this host (bind 0.0.0.0)
+OLLAMA_CHAT_MODEL=qwen2.5:7b
+WHISPER_DEVICE=cuda
+WHISPER_COMPUTE_TYPE=float16
+BROWSER_CONTROL_URL=http://192.168.10.5:8777   # drive the app host's Chrome
+COMPOSE_FILE=docker-compose.yml:docker-compose.gpu-linux.yml   # GPU (":" on Linux)
+
+# Ollama runs on this host (systemd or a container) listening on 0.0.0.0:11434.
+docker compose up -d javis      # brain bridge only (no bot, no desktop)
+```
+
+### App host (.5 — bot + browser, no GPU)
+
+```
+# .env
+JARVIS_ROLE=app
+BRIDGE_URL=http://192.168.10.9:8765            # offload STT/LLM/TTS to the brain
+CDP_PUBLISH_BIND=0.0.0.0                        # publish control-server 8777 to the LAN
+STREAM_HW=0                                     # no NVENC on a no-GPU host
+DISCORD_SELFBOT_TOKEN=...
+DISCORD_GUILD_ID=...
+# no GPU → leave COMPOSE_FILE unset (base compose only)
+
+docker compose up -d javis      # bot + desktop + Chrome + control-server
+```
+
+The `brain` and `app` roles are backward-compatible additions to `full`/`browser`
+/`bot`; see `docker/run-if-role.sh`.
+
 ## Windows 11 notes
 
 - Install the NVIDIA driver on Windows and enable GPU in Docker Desktop