add El SDK CI/CD pipeline and install script

- .gitea/workflows/sdk-release.yaml: build elc from bootstrap, run tests,
  publish latest release, dispatch el-sdk-updated to downstream repos
- install.sh: one-command El SDK install from Gitea release

.gitea/workflows/sdk-release.yaml

@@ -0,0 +1,166 @@
+name: El SDK Release
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  build-and-release:
+    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
+
+      # Gen2: compile the bootstrap C source into a working elc binary
+      - name: Build elc from bootstrap (gen2)
+        run: |
+          gcc -O2 \
+            -I el-compiler/runtime \
+            dist/elc-bootstrap.c \
+            el-compiler/runtime/el_runtime.c \
+            -lcurl -lpthread \
+            -o dist/elc-gen2
+          chmod +x dist/elc-gen2
+          echo "gen2 elc built"
+          dist/elc-gen2 --version || true
+
+      # Gen3: use gen2 to compile the El compiler from its own El source (self-host)
+      - name: Self-host: compile El compiler with gen2 (gen3)
+        run: |
+          mkdir -p dist/platform
+          dist/elc-gen2 el-compiler/src/compiler.el > dist/elc-gen3.c
+          gcc -O2 \
+            -I el-compiler/runtime \
+            dist/elc-gen3.c \
+            el-compiler/runtime/el_runtime.c \
+            -lcurl -lpthread \
+            -o dist/platform/elc
+          chmod +x dist/platform/elc
+          echo "gen3 (self-hosted) elc built"
+          dist/platform/elc --version || true
+
+      # Run all four test suites with gen3 elc
+      - name: Run tests — text
+        run: |
+          ELC="$(pwd)/dist/platform/elc" \
+          EL_HOME="$(pwd)" \
+          bash tests/text/run.sh
+
+      - name: Run tests — calendar
+        run: |
+          ELC="$(pwd)/dist/platform/elc" \
+          EL_HOME="$(pwd)" \
+          bash tests/calendar/run.sh
+
+      - name: Run tests — time
+        run: |
+          ELC="$(pwd)/dist/platform/elc" \
+          EL_HOME="$(pwd)" \
+          bash tests/time/run.sh
+
+      - name: Run tests — html_sanitizer
+        run: |
+          ELC="$(pwd)/dist/platform/elc" \
+          EL_HOME="$(pwd)" \
+          bash tests/html_sanitizer/run.sh
+
+      # Publish / update the `latest` release with the three SDK assets
+      - name: Publish latest release
+        env:
+          GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
+          GITEA_API: https://git.neuralplatform.ai/api/v1
+          REPO: neuron-technologies/el
+        run: |
+          # Delete existing `latest` release if it exists
+          EXISTING_ID=$(curl -sf \
+            -H "Authorization: token ${GITEA_TOKEN}" \
+            "${GITEA_API}/repos/${REPO}/releases/tags/latest" \
+            | python3 -c "import sys,json; d=json.load(sys.stdin); print(d['id'])" 2>/dev/null || true)
+
+          if [ -n "${EXISTING_ID}" ]; then
+            echo "Deleting existing release id=${EXISTING_ID}"
+            curl -sf -X DELETE \
+              -H "Authorization: token ${GITEA_TOKEN}" \
+              "${GITEA_API}/repos/${REPO}/releases/${EXISTING_ID}"
+          fi
+
+          # Delete and re-create the `latest` tag so it points at HEAD
+          curl -sf -X DELETE \
+            -H "Authorization: token ${GITEA_TOKEN}" \
+            "${GITEA_API}/repos/${REPO}/tags/latest" || true
+
+          # Create the release
+          RELEASE_ID=$(curl -sf -X POST \
+            -H "Authorization: token ${GITEA_TOKEN}" \
+            -H "Content-Type: application/json" \
+            "${GITEA_API}/repos/${REPO}/releases" \
+            -d "{
+              \"tag_name\": \"latest\",
+              \"name\": \"El SDK (latest)\",
+              \"body\": \"Latest El SDK build from commit ${GITHUB_SHA}.\nBuilt $(date -u +%Y-%m-%dT%H:%M:%SZ).\",
+              \"draft\": false,
+              \"prerelease\": false
+            }" | python3 -c "import sys,json; print(json.load(sys.stdin)['id'])")
+
+          echo "Created release id=${RELEASE_ID}"
+
+          # Upload assets
+          upload_asset() {
+            local filepath="$1"
+            local name="$2"
+            echo "Uploading ${name}..."
+            curl -sf -X POST \
+              -H "Authorization: token ${GITEA_TOKEN}" \
+              -F "attachment=@${filepath};filename=${name}" \
+              "${GITEA_API}/repos/${REPO}/releases/${RELEASE_ID}/assets"
+          }
+
+          upload_asset dist/platform/elc                elc
+          upload_asset el-compiler/runtime/el_runtime.c el_runtime.c
+          upload_asset el-compiler/runtime/el_runtime.h el_runtime.h
+
+          echo "Release published successfully"
+
+      # Dispatch el-sdk-updated event to downstream repos
+      - name: Dispatch to foundation/engram
+        env:
+          GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
+          GITEA_API: https://git.neuralplatform.ai/api/v1
+        run: |
+          curl -sf -X POST \
+            -H "Authorization: token ${GITEA_TOKEN}" \
+            -H "Content-Type: application/json" \
+            "${GITEA_API}/repos/neuron-technologies/engram/dispatches" \
+            -d "{
+              \"type\": \"el-sdk-updated\",
+              \"inputs\": {
+                \"el_version\": \"latest\",
+                \"commit\": \"${GITHUB_SHA}\"
+              }
+            }"
+          echo "Dispatched el-sdk-updated to foundation/engram"
+
+      - name: Dispatch to neuron-technologies/forge
+        env:
+          GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
+          GITEA_API: https://git.neuralplatform.ai/api/v1
+        run: |
+          curl -sf -X POST \
+            -H "Authorization: token ${GITEA_TOKEN}" \
+            -H "Content-Type: application/json" \
+            "${GITEA_API}/repos/neuron-technologies/forge/dispatches" \
+            -d "{
+              \"type\": \"el-sdk-updated\",
+              \"inputs\": {
+                \"el_version\": \"latest\",
+                \"commit\": \"${GITHUB_SHA}\"
+              }
+            }"
+          echo "Dispatched el-sdk-updated to neuron-technologies/forge"