feat(backend): make cli interactive

backend/cli/main.py

@@ -15,6 +15,7 @@ from .commands import (
     # Service commands
     cmd_services_list, setup_services_parser,
 )
+from .interactive import run_interactive_mode
 
 
 def setup_parser() -> argparse.ArgumentParser:
@@ -41,7 +42,22 @@ def main():
     args = parser.parse_args()
     
     if not args.command:
-        parser.print_help()
+        # Launch interactive mode when no command is provided
+        try:
+            cli = NimbusFlowCLI()
+            run_interactive_mode(cli)
+        except CLIError as e:
+            print(f"❌ Error: {e}")
+            return 1
+        except KeyboardInterrupt:
+            print("\n🛑 Interrupted by user")
+            return 1
+        except Exception as e:
+            print(f"❌ Unexpected error: {e}")
+            return 1
+        finally:
+            if 'cli' in locals():
+                cli.close()
         return
     
     try: