feat: add demo Main entry point for banking system simulation

src/main/java/dev/banking/Main.java

@@ -0,0 +1,47 @@
+package dev.banking;
+
+import dev.banking.service.BankingSystem;
+import dev.banking.DemoFactory;
+
+/**
+ * Entry point of the application.
+ *
+ * This class is provided for demonstration purposes only.
+ *
+ * IMPORTANT:
+ * - Do NOT modify this file.
+ * - This file is NOT used during grading.
+ * - All grading is performed through the provided JUnit tests.
+ */
+public final class Main {
+
+    private Main() {
+    }
+
+    public static void main(String[] args) {
+
+        System.out.println("=================================");
+        System.out.println(" Advanced Banking System");
+        System.out.println("=================================");
+
+        try {
+
+            BankingSystem bankingSystem =
+                    DemoFactory.createDemoSystem();
+
+            System.out.println("System initialized...");
+            System.out.println("Running simulation with concurrent workers...\n");
+
+//            bankingSystem.start();
+
+            System.out.println("\n=================================");
+            System.out.println("Simulation completed successfully.");
+            System.out.println("=================================");
+
+        } catch (Exception e) {
+
+            System.err.println("\nUnexpected error occurred:");
+            e.printStackTrace();
+        }
+    }
+}