refactor: create a .gitignore file in the root directory

.gitignore

@@ -0,0 +1,71 @@
+# Common
+.DS_Store
+.idea/
+*.iws
+*.iml
+*.ipr
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.log
+*.swp
+
+# Frontend workspace
+/frontend/**/node_modules/
+/frontend/**/.eslintcache
+/frontend/**/tsconfig.tsbuildinfo
+/frontend/**/*.local
+
+# Frontend app
+/frontend/app/dist/
+/frontend/app/deploy_versions/
+/frontend/app/.temp/
+/frontend/app/.rn_temp/
+/frontend/app/.swc
+
+# Frontend web
+/frontend/web/dist/
+/frontend/web/dist-ssr/
+/frontend/web/report.html
+/frontend/web/yarn.lock
+/frontend/web/npm-debug.log*
+/frontend/web/.pnpm-error.log*
+/frontend/web/.pnpm-debug.log
+/frontend/web/tests/**/coverage/
+/frontend/web/.vscode/launch.json
+
+# Backend build tools
+/backend/.gradle/
+/backend/build/
+!/backend/gradle/wrapper/gradle-wrapper.jar
+/backend/**/target/
+!/backend/.mvn/wrapper/maven-wrapper.jar
+
+# Backend IDE
+/backend/**/.apt_generated
+/backend/**/.classpath
+/backend/**/.factorypath
+/backend/**/.project
+/backend/**/.settings/
+/backend/**/.springBeans
+
+# Backend JRebel
+/backend/**/rebel.xml
+
+# Backend NetBeans
+/backend/nbproject/private/
+/backend/build/*
+/backend/nbbuild/
+/backend/dist/
+/backend/nbdist/
+/backend/.nb-gradle/
+
+# Backend generated files
+/backend/**/*.xml.versionsBackup
+!/backend/*/build/*.java
+!/backend/*/build/*.html
+!/backend/*/build/*.xml
+
+# Backend local configuration
+/backend/agileboot-admin/src/main/resources/application-prod.yml