ci: skip elb on Linux — compile dist/soul.c directly to prevent OOM

elb runs elc which consumes 24GB+ virtual memory on the 16GB GCE runner,
OOM-killing the runner process and crashing the VM. We already restore the
repo's pre-built soul.c immediately after elb runs, so elb's output is
discarded anyway. Skip elb entirely: download only the El runtime headers
and compile dist/soul.c directly.

Root cause: runner VM was unresponsive for 7+ weeks due to repeated elc
OOM kills. VM was manually reset 2026-06-28 to restore CI.

.gitea/workflows/ci.yaml

@@ -43,7 +43,7 @@ jobs:
             > /etc/apt/sources.list.d/google-cloud-sdk.list
           apt-get update -qq && apt-get install -y google-cloud-cli
 
-      - name: Download El SDK from Artifact Registry
+      - name: Download El runtime from Artifact Registry
         env:
           GCP_SA_KEY: ${{ secrets.GCP_SA_KEY }}
         run: |
@@ -51,10 +51,12 @@ jobs:
           gcloud auth activate-service-account --key-file=/tmp/gcp-key.json
           gcloud config set project neuron-785695
 
-          rm -rf /opt/el/dist /opt/el/runtime
-          mkdir -p /opt/el/dist/platform /opt/el/dist/bin /opt/el/runtime
+          rm -rf /opt/el/runtime
+          mkdir -p /opt/el/runtime
 
-          # Get latest version of each package
+          # Get latest version of each runtime package (elc/elb not needed — we compile
+          # dist/soul.c directly; running elb on Linux OOM-kills the runner, and we
+          # always use the repo's pre-built soul.c anyway).
           get_latest() {
             gcloud artifacts versions list \
               --repository=foundation-prod \
@@ -66,22 +68,10 @@ jobs:
               --format="value(name)" 2>/dev/null | awk -F/ '{print $NF}'
           }
 
-          ELC_VER=$(get_latest el-elc)
-          ELB_VER=$(get_latest el-elb)
           RC_VER=$(get_latest el-runtime-c)
           RH_VER=$(get_latest el-runtime-h)
 
-          echo "Downloading elc@${ELC_VER} elb@${ELB_VER} runtime@${RC_VER}"
-
-          gcloud artifacts generic download \
-            --repository=foundation-prod --location=us-central1 --project=neuron-785695 \
-            --package=el-elc --version="${ELC_VER}" \
-            --destination=/opt/el/dist/platform/
-
-          gcloud artifacts generic download \
-            --repository=foundation-prod --location=us-central1 --project=neuron-785695 \
-            --package=el-elb --version="${ELB_VER}" \
-            --destination=/opt/el/dist/bin/
+          echo "Downloading runtime@${RC_VER}"
 
           gcloud artifacts generic download \
             --repository=foundation-prod --location=us-central1 --project=neuron-785695 \
@@ -93,39 +83,20 @@ jobs:
             --package=el-runtime-h --version="${RH_VER}" \
             --destination=/opt/el/runtime/
 
-          # Downloaded files keep original names; rename to canonical paths
-          mv /opt/el/dist/platform/elc* /opt/el/dist/platform/elc 2>/dev/null || true
-          mv /opt/el/dist/bin/elb*       /opt/el/dist/bin/elb      2>/dev/null || true
           mv /opt/el/runtime/el_runtime.c* /opt/el/runtime/el_runtime.c 2>/dev/null || true
           mv /opt/el/runtime/el_runtime.h* /opt/el/runtime/el_runtime.h 2>/dev/null || true
-
-          chmod +x /opt/el/dist/platform/elc /opt/el/dist/bin/elb
-          echo "El SDK ready"
-          /opt/el/dist/platform/elc --version || true
+          echo "El runtime ready: $(ls /opt/el/runtime/)"
 
       - name: Build neuron soul binary
         run: |
-          ELB=/opt/el/dist/bin/elb
-          ELC=/opt/el/dist/platform/elc
           RUNTIME=/opt/el/runtime
 
-          # Preserve the pre-compiled dist/soul.c from the repo before running elb.
-          # elb may overwrite it during compilation; we always want the repo version
-          # since it contains the patched self-contained translation unit (all modules
-          # inlined, workspace scope fix, agentic dedup fix, etc.).
-          cp dist/soul.c /tmp/soul.c.prebuilt
-
-          # Compile all El modules to C via elb.
-          # elb fails at link on Linux (GNU ld rejects duplicate strong symbols that
-          # macOS ld accepts silently) — that's expected and captured with || true.
-          $ELB --elc=$ELC --runtime=$RUNTIME/el_runtime.c || true
-
-          # Restore the repo's self-contained soul.c — elb may have overwritten it
-          # with a partial (non-inlined) version that lacks module-level definitions.
-          cp /tmp/soul.c.prebuilt dist/soul.c
-
-          # Compile the self-contained translation unit.  No --allow-multiple-definition
-          # needed since soul.c inlines all modules.
+          # Compile the self-contained translation unit directly from dist/soul.c.
+          # dist/soul.c is the authoritative combined unit maintained in the repo —
+          # regenerated on macOS by running elb (which succeeds on arm64/macOS ld but
+          # fails on Linux due to duplicate strong symbols). We skip the elb step here
+          # entirely: elb on Linux would OOM the runner (elc uses 24GB+ virtual memory
+          # on a 16GB host) and we always restore from the repo's soul.c anyway.
           mkdir -p dist
           cc -O2 -DHAVE_CURL \
             -I$RUNTIME \