Fix version display issues, container shutdown problems, and modernize build scripts

package.json

@@ -1,6 +1,6 @@
 {
   "name": "jmespath-playground",
-  "version": "1.2.2",
+  "version": "1.2.3",
   "description": "A React-based web application for testing JMESPath expressions against JSON data",
   "main": "index.js",
   "scripts": {
@@ -9,7 +9,8 @@
     "build": "react-scripts build",
     "test": "react-scripts test --watchAll=false",
     "test:watch": "react-scripts test",
-    "server": "node server.js"
+    "server": "node server.js",
+    "build-image": "node scripts/build-image.js"
   },
   "engines": {
     "node": ">=24.0.0"