fix: batch 4 — connection pooling, graceful shutdown, email verification UX

- Prisma: connection_limit=10, pool_timeout=30 on DATABASE_URL in both compose files
- Graceful shutdown: SIGTERM/SIGINT forwarded to Node process in docker-entrypoint.sh
- testEmailConnection: replaced real email send with transporter.verify(), simplified UI to single button
- NotificationLog.userId index: confirmed already present, no change needed

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

docker/docker-compose.dev.yml

@@ -68,7 +68,7 @@ services:
     env_file:
       - ../.env
     environment:
-      - DATABASE_URL=postgresql://${POSTGRES_USER:-mopc}:${POSTGRES_PASSWORD:-devpassword}@postgres:5432/${POSTGRES_DB:-mopc}
+      - DATABASE_URL=postgresql://${POSTGRES_USER:-mopc}:${POSTGRES_PASSWORD:-devpassword}@postgres:5432/${POSTGRES_DB:-mopc}?connection_limit=10&pool_timeout=30
       - NEXTAUTH_URL=${NEXTAUTH_URL:-http://localhost:3000}
       - NEXTAUTH_SECRET=${NEXTAUTH_SECRET:-dev-secret-key-for-local-development-only}
       - AUTH_SECRET=${AUTH_SECRET:-dev-secret-key-for-local-development-only}

docker/docker-compose.yml

@@ -23,7 +23,7 @@ services:
       - .env
     environment:
       - NODE_ENV=production
-      - DATABASE_URL=postgresql://mopc:${DB_PASSWORD}@postgres:5432/mopc
+      - DATABASE_URL=postgresql://mopc:${DB_PASSWORD}@postgres:5432/mopc?connection_limit=10&pool_timeout=30
       - NEXTAUTH_URL=${NEXTAUTH_URL}
       - NEXTAUTH_SECRET=${NEXTAUTH_SECRET}
       - AUTH_SECRET=${NEXTAUTH_SECRET}

docker/docker-entrypoint.sh

@@ -59,4 +59,18 @@ else
 fi
 
 echo "==> Starting application..."
-exec node server.js
+
+# Graceful shutdown: forward SIGTERM/SIGINT to the Node process
+# so in-flight requests can complete before the container exits.
+shutdown() {
+  echo "==> Received shutdown signal, stopping gracefully..."
+  kill -TERM "$NODE_PID" 2>/dev/null
+  wait "$NODE_PID"
+  exit $?
+}
+
+trap shutdown TERM INT
+
+node server.js &
+NODE_PID=$!
+wait "$NODE_PID"