Add PM2 setup to deployment script

Add a start script using vite preview on port 4174 and replace the
static file copy step in deploy.sh with PM2 start/reload logic.

scripts/deploy.sh

@@ -3,7 +3,6 @@ set -e
 
 APP_NAME="tietokonepaja-fi"
 APP_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
-DEPLOY_DIR="/var/www/tietokonepaja-fi"
 
 echo "Deploying $APP_NAME from $APP_DIR..."
 
@@ -18,7 +17,13 @@ sudo bun install
 echo "Building application..."
 sudo bun run build
 
-echo "Copying to $DEPLOY_DIR..."
-sudo cp -r dist/. "$DEPLOY_DIR"
+echo "Starting/reloading with pm2..."
+if pm2 describe "$APP_NAME" > /dev/null 2>&1; then
+  pm2 reload "$APP_NAME" --update-env
+else
+  pm2 start bun --name "$APP_NAME" -- run start
+fi
+
+pm2 save
 
 echo "Deployment complete."