Add post-deploy health check template

Template script for project-specific health checks. Copy to
scripts/health-check.sh — CD workflows run it automatically.

scripts/health-check-template.sh

@@ -0,0 +1,50 @@
+#!/usr/bin/env bash
+# Post-deploy health check template.
+# Copy to your project as scripts/health-check.sh and customize.
+# Called automatically by CD workflows after deploy.
+# Args: $1 = stack name, $2 = AWS region
+
+set -euo pipefail
+
+STACK_NAME="${1:?Stack name required}"
+REGION="${2:-us-east-1}"
+
+echo "Running health checks for ${STACK_NAME}..."
+
+# Example: verify a Lambda function is invocable
+# FUNCTION_NAME="${STACK_NAME}-process-order"
+# aws lambda invoke \
+#   --function-name "$FUNCTION_NAME" \
+#   --payload '{"healthCheck": true}' \
+#   --region "$REGION" \
+#   /tmp/health-check-response.json
+# cat /tmp/health-check-response.json
+
+# Example: verify an EC2 instance is running
+# INSTANCE_ID=$(aws cloudformation describe-stacks \
+#   --stack-name "$STACK_NAME" \
+#   --query 'Stacks[0].Outputs[?OutputKey==`InstanceId`].OutputValue' \
+#   --output text --region "$REGION")
+# STATE=$(aws ec2 describe-instances \
+#   --instance-ids "$INSTANCE_ID" \
+#   --query 'Reservations[0].Instances[0].State.Name' \
+#   --output text --region "$REGION")
+# if [[ "$STATE" != "running" ]]; then
+#   echo "ERROR: Instance $INSTANCE_ID is $STATE, expected running"
+#   exit 1
+# fi
+# echo "Instance $INSTANCE_ID is running."
+
+# Example: verify an API Gateway endpoint responds
+# API_URL=$(aws cloudformation describe-stacks \
+#   --stack-name "$STACK_NAME" \
+#   --query 'Stacks[0].Outputs[?OutputKey==`ApiUrl`].OutputValue' \
+#   --output text --region "$REGION")
+# HTTP_CODE=$(curl -sf -o /dev/null -w '%{http_code}' "$API_URL/health")
+# if [[ "$HTTP_CODE" != "200" ]]; then
+#   echo "ERROR: API health endpoint returned $HTTP_CODE"
+#   exit 1
+# fi
+# echo "API endpoint healthy."
+
+echo "All health checks passed."