Add OCaml SX kernel build to sx_docs Docker image and enable in production

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

docker-compose.yml

@@ -228,6 +228,8 @@ services:
       <<: *app-env
       REDIS_URL: redis://redis:6379/10
       WORKERS: "1"
+      SX_USE_OCAML: "1"
+      SX_OCAML_BIN: "/app/bin/sx_server"
 
   db:
     image: postgres:16

sx/Dockerfile

@@ -1,5 +1,16 @@
 # syntax=docker/dockerfile:1
 
+# --- Stage 1: Build OCaml SX kernel ---
+FROM ocaml/opam:debian-12-ocaml-5.2 AS ocaml-build
+USER opam
+WORKDIR /home/opam/sx
+COPY --chown=opam:opam hosts/ocaml/dune-project ./
+COPY --chown=opam:opam hosts/ocaml/lib/ ./lib/
+COPY --chown=opam:opam hosts/ocaml/bin/dune hosts/ocaml/bin/run_tests.ml \
+     hosts/ocaml/bin/debug_set.ml hosts/ocaml/bin/sx_server.ml ./bin/
+RUN eval $(opam env) && dune build bin/sx_server.exe
+
+# --- Stage 2: Python app ---
 FROM python:3.11-slim AS base
 
 ENV PYTHONDONTWRITEBYTECODE=1 \
@@ -49,6 +60,9 @@ COPY likes/models/ ./likes/models/
 COPY orders/__init__.py ./orders/__init__.py
 COPY orders/models/ ./orders/models/
 
+# OCaml SX kernel binary
+COPY --from=ocaml-build /home/opam/sx/_build/default/bin/sx_server.exe /app/bin/sx_server
+
 COPY sx/entrypoint.sh /usr/local/bin/entrypoint.sh
 RUN chmod +x /usr/local/bin/entrypoint.sh