perf(deploy): pre-install node_modules in CI and enable always-on to fix slow cold start

- CI now runs pnpm install and includes node_modules in the zip artifact
- startup.sh simplified: removed pnpm install fallback, uses direct bin path instead of npx
- Azure Web App always-on enabled to prevent cold starts

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

.github/workflows/deploy-langgraph.yml

@@ -25,15 +25,23 @@ jobs:
         with:
           node-version: "20"
 
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v4
+        with:
+          version: 10
+
+      - name: Install dependencies
+        run: |
+          cd langgraph
+          pnpm install --frozen-lockfile
+
       - name: Package for deployment
         run: |
           cd langgraph
-          # Create langgraphjs dev prerequisites
           touch .env
           mkdir -p .langgraph_api
-          # Package source only — Oryx will install node_modules on Azure
           zip -r ../deploy-langgraph.zip . \
-            -x "node_modules/*" ".git/*" "dist/*" ".DS_Store"
+            -x ".git/*" "dist/*" ".DS_Store"
 
       - name: Login to Azure
         uses: azure/login@v2

langgraph/startup.sh

@@ -9,17 +9,5 @@ cd /home/site/wwwroot
 touch .env
 mkdir -p .langgraph_api
 
-# Install pnpm globally if not available
-if ! command -v pnpm &> /dev/null; then
-  echo "Installing pnpm..."
-  npm install -g pnpm@10
-fi
-
-# Install dependencies if node_modules is missing (Oryx should have done this, but fallback)
-if [ ! -d "node_modules" ]; then
-  echo "node_modules not found, installing dependencies..."
-  pnpm install --frozen-lockfile
-fi
-
 echo "Starting LangGraph server on port ${PORT:-8080}..."
-exec npx langgraphjs dev --host 0.0.0.0 --port ${PORT:-8080} --no-browser
+exec ./node_modules/.bin/langgraphjs dev --host 0.0.0.0 --port ${PORT:-8080} --no-browser