Remove binary .class files from Git and add .gitignore

.gitignore

@@ -0,0 +1,33 @@
+# Compiled class files
+*.class
+
+# Build directories
+WebContent/WEB-INF/classes/
+
+# Log files
+*.log
+logs/
+
+# OS files
+.DS_Store
+Thumbs.db
+
+# IDE files
+.settings/
+.classpath
+.project
+
+# Environment files (보안상 제외)
+.env
+.env.development
+.env.production
+
+# Temporary files
+*.tmp
+*.bak
+*.swp
+*~
+
+# Docker volumes
+.docker/
+