switch frontend css from bootstrap to bulma

Foxnouns.Backend/Controllers/UsersController.cs

@@ -1,4 +1,3 @@
-using System.Diagnostics;
 using Foxnouns.Backend.Database;
 using Foxnouns.Backend.Middleware;
 using Foxnouns.Backend.Services;

Foxnouns.Backend/Database/Models/Cache.cs

@@ -0,0 +1,11 @@
+using NodaTime;
+
+namespace Foxnouns.Backend.Database.Models;
+
+public class Cache
+{
+    public long Id { get; init; }
+    public required string Key { get; init; }
+    public required string Value { get; set; }
+    public Instant Expires { get; init; }
+}