Add DevSecOpsApp code with updated Jenkins pipeline for multi-environment deployment

.gitignore

@@ -1,3 +1,20 @@
+# Dependencies
+node_modules/
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+
+# Production builds
+/build
+/dist
+
+# Environment variables
+.env
+.env.local
+.env.development.local
+.env.test.local
+.env.production.local
+
 # IDE
 .vscode/
 .idea/
@@ -8,15 +25,22 @@
 .DS_Store
 Thumbs.db
 
-# Dependencies
-node_modules/
-package-lock.json
-yarn.lock
+# Logs
+logs/
+*.log
 
-# Build
-dist/
-build/
+# Runtime data
+pids/
+*.pid
+*.seed
+*.pid.lock
 
-# Environment
-.env
-.env.local
+# Coverage directory used by tools like istanbul
+coverage/
+
+# Docker
+.dockerignore
+
+# Temporary files
+tmp/
+temp/