ci: add neuron soul build pipeline

Downloads El SDK from Artifact Registry, generates ELP declarations header,
builds the neuron soul binary with elb, smoke-tests it, and publishes to
foundation-dev on push to main.

.gitea/workflows/ci.yaml

@@ -0,0 +1,140 @@
+name: Neuron Soul CI
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Install build dependencies
+        run: |
+          apt-get update -qq
+          apt-get install -y gcc libcurl4-openssl-dev apt-transport-https ca-certificates python3
+          echo "deb [trusted=yes] https://packages.cloud.google.com/apt cloud-sdk main" \
+            > /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
+        env:
+          GCP_SA_KEY: ${{ secrets.GCP_SA_KEY }}
+        run: |
+          echo "${GCP_SA_KEY}" > /tmp/gcp-key.json
+          gcloud auth activate-service-account --key-file=/tmp/gcp-key.json
+          gcloud config set project neuron-785695
+
+          mkdir -p /opt/el/dist/platform /opt/el/dist/bin /opt/el/runtime
+
+          # Get latest version of each package
+          get_latest() {
+            gcloud artifacts versions list \
+              --repository=foundation-dev \
+              --location=us-central1 \
+              --project=neuron-785695 \
+              --package="$1" \
+              --sort-by="~createTime" \
+              --limit=1 \
+              --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-dev --location=us-central1 --project=neuron-785695 \
+            --package=el-elc --version="${ELC_VER}" \
+            --destination=/opt/el/dist/platform/
+
+          gcloud artifacts generic download \
+            --repository=foundation-dev --location=us-central1 --project=neuron-785695 \
+            --package=el-elb --version="${ELB_VER}" \
+            --destination=/opt/el/dist/bin/
+
+          gcloud artifacts generic download \
+            --repository=foundation-dev --location=us-central1 --project=neuron-785695 \
+            --package=el-runtime-c --version="${RC_VER}" \
+            --destination=/opt/el/runtime/
+
+          gcloud artifacts generic download \
+            --repository=foundation-dev --location=us-central1 --project=neuron-785695 \
+            --package=el-runtime-h --version="${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
+
+      - name: Generate ELP master declarations header
+        run: |
+          python3 - <<'PYEOF'
+import os, re
+dist = 'dist'
+decls = set()
+guard_pat = re.compile(r'^(el_val_t|void|int|char\*|const char\*)\s+\w+\s*\(')
+for fn in sorted(os.listdir(dist)):
+    if not fn.endswith('.c'):
+        continue
+    with open(os.path.join(dist, fn)) as f:
+        for line in f:
+            line = line.rstrip()
+            if guard_pat.match(line) and line.endswith(';'):
+                decls.add(line)
+header = ['/* Auto-generated C forward declarations for ELP cross-module calls */',
+          '#pragma once', '#include "el_runtime.h"', '']
+header += sorted(decls)
+with open(os.path.join(dist, 'elp-c-decls.h'), 'w') as f:
+    f.write('\n'.join(header) + '\n')
+print(f"Generated elp-c-decls.h with {len(decls)} declarations")
+PYEOF
+
+      - name: Build neuron soul binary
+        run: |
+          ELB=/opt/el/dist/bin/elb
+          ELC=/opt/el/dist/platform/elc
+          RUNTIME=/opt/el/runtime
+
+          $ELB --elc=$ELC --runtime=$RUNTIME
+          ls -lh dist/neuron
+
+      - name: Smoke test
+        run: |
+          file dist/neuron
+          timeout 3 dist/neuron --help 2>&1 || true
+          echo "smoke test complete"
+
+      - name: Publish neuron binary
+        if: github.event_name == 'push'
+        env:
+          GCP_SA_KEY: ${{ secrets.GCP_SA_KEY }}
+        run: |
+          VERSION="${GITEA_SHA:0:8}"
+
+          gcloud artifacts generic upload \
+            --repository=foundation-dev \
+            --location=us-central1 \
+            --project=neuron-785695 \
+            --package=neuron-soul \
+            --version="${VERSION}" \
+            --source=dist/neuron
+
+          echo "Published neuron-soul@${VERSION}"
+          rm -f /tmp/gcp-key.json