Added system controller to handle potential future API changes

Author: XIYUEKONGLING

OpenBioCardServer/Controllers/Classic/ClassicSystemController.cs

@@ -0,0 +1,19 @@
+using Microsoft.AspNetCore.Mvc;
+using OpenBioCardServer.Data;
+
+namespace OpenBioCardServer.Controllers.Classic;
+
+[Route("classic")]
+[ApiController]
+public class ClassicSystemController : ControllerBase
+{
+    private readonly AppDbContext _context;
+    private readonly ILogger<ClassicAuthController> _logger;
+
+    public ClassicSystemController(AppDbContext context,
+        ILogger<ClassicAuthController> logger)
+    {
+        _context = context;
+        _logger = logger;
+    }
+}