Added diagnose frontend and backend implementation

Moonlight.Api/Http/Controllers/Admin/DiagnoseController.cs

@@ -0,0 +1,29 @@
+using Microsoft.AspNetCore.Mvc;
+using Moonlight.Api.Mappers;
+using Moonlight.Api.Services;
+using Moonlight.Shared.Http.Responses.Admin;
+
+namespace Moonlight.Api.Http.Controllers.Admin;
+
+[ApiController]
+[Route("api/admin/system/diagnose")]
+public class DiagnoseController : Controller
+{
+    private readonly DiagnoseService DiagnoseService;
+
+    public DiagnoseController(DiagnoseService diagnoseService)
+    {
+        DiagnoseService = diagnoseService;
+    }
+
+    [HttpGet]
+    public async Task<ActionResult<DiagnoseResultResponse[]>> GetAsync()
+    {
+        var results = await DiagnoseService.DiagnoseAsync();
+
+        return results
+            .OrderBy(x => x.Level)
+            .MapToResult()
+            .ToArray();
+    }
+}