feat: cross-platform compose (Ubuntu CDI + Windows Docker Desktop GPU)

Base compose is GPU-agnostic; GPU is added by a per-OS override selected via
COMPOSE_FILE in .env (docker-compose.gpu-linux.yml for Ubuntu/CDI,
docker-compose.gpu-windows.yml for Windows 11 Docker Desktop). Adds .env.example
split-deployment section + docs/DEPLOY.md covering all-in-one and browser+bot
layouts on both OSes.

docker-compose.gpu-linux.yml

@@ -0,0 +1,14 @@
+# GPU override for LINUX hosts using nvidia-container-toolkit with CDI
+# (Ubuntu local Docker). Verified on the RTX 5050 (Blackwell sm_120).
+#
+#   docker compose -f docker-compose.yml -f docker-compose.gpu-linux.yml up -d
+#
+# Or set COMPOSE_FILE in .env (recommended):
+#   COMPOSE_FILE=docker-compose.yml:docker-compose.gpu-linux.yml
+services:
+  ollama:
+    devices:
+      - "nvidia.com/gpu=all"
+  javis:
+    devices:
+      - "nvidia.com/gpu=all"