Switch CI from build-stage.sh to elb — no OOM

elb compiles each .el source independently (per-file codegen),
avoiding the exponential memory growth from concatenating all sources
into main-combined.el and feeding it to elc in one shot.

- dev.yaml: replace build-stage.sh with elb build + per-file JS elc
- Dockerfile.stage: COPY dist/neuron-landing (elb binary) directly
  instead of compiling from pre-generated main.c. soul-demo stays as
  cc compilation (small file, no risk).

Dockerfile.stage

@@ -4,12 +4,14 @@
 #   - neuron-web  on port 8080 (landing page server)
 #   - soul-demo   on port 7772 (demo chat, localhost only)
 #
-# bootstrap.py is no longer in the build path. The host-side build-stage.sh
-# pre-compiles src/*.el → dist/main.c using the canonical native elc and
-# applies the stub forward-declaration sed before this Dockerfile runs.
-# The image just compiles the finished C source.
+# neuron-web is built by `elb build` in CI (not here). elb compiles each
+# .el source independently and links the result — no combined mega-file,
+# no exponential memory growth. The binary lands at dist/neuron-landing
+# (linux/amd64) and is COPY'd directly into the runtime image.
+#
+# soul-demo.c is pre-committed (small, no OOM risk) and compiled here.
 
-# ── Stage 1: compile both binaries ────────────────────────────────────────────
+# ── Stage 1: compile soul-demo ────────────────────────────────────────────────
 FROM debian:bookworm-slim AS builder
 
 RUN apt-get update \
@@ -22,30 +24,10 @@ RUN apt-get update \
 
 WORKDIR /build
 
-# El runtime (shared by both binaries)
 COPY runtime/el_runtime.c runtime/el_runtime.h ./
-
-# Pre-compile el_runtime as a separate cached layer.
-# el_runtime.c changes rarely; main.c changes every run.
-# Splitting this out means el_runtime.o is cached across builds when only main.c changes.
 RUN cc -O2 -c el_runtime.c -I. -o el_runtime.o
 
-# ── Build neuron-web ──────────────────────────────────────────────────────────
-#
-# main.c was generated on the host by build-stage.sh from src/*.el via the
-# native elc compiler. Stub forward-declarations were already injected on
-# the host side, so this stage is a straight cc invocation.
-COPY dist/web_stubs.c ./
-COPY dist/main.c ./
-
-RUN cc -O2 -rdynamic \
-       -o neuron-web \
-       main.c web_stubs.c el_runtime.o \
-       -lcurl -lpthread -ldl -lm -lssl -lcrypto
-
-# ── Build soul-demo ───────────────────────────────────────────────────────────
-COPY dist/soul-demo.c ./
-COPY dist/vessel_stubs.c ./
+COPY dist/soul-demo.c dist/vessel_stubs.c ./
 
 RUN cc -O2 -rdynamic \
        -o soul-demo \
@@ -66,8 +48,11 @@ RUN apt-get update \
  && mkdir -p /srv/soul/engram-demo \
  && chown -R landing:landing /srv/landing /srv/soul
 
-COPY --from=builder /build/neuron-web /usr/local/bin/neuron-web
-COPY --from=builder /build/soul-demo  /usr/local/bin/soul-demo
+# neuron-web binary — produced by `elb build` in CI (linux/amd64)
+COPY dist/neuron-landing /usr/local/bin/neuron-web
+RUN chmod +x /usr/local/bin/neuron-web
+
+COPY --from=builder /build/soul-demo /usr/local/bin/soul-demo
 
 # Engram snapshot — baked in so soul has memory from cold start
 COPY dist/engram-snapshot.json /srv/soul/engram-demo/snapshot.json