added auth with a simple UI

api/OED.Api/Infrastructure/Auth/SessionService.cs

@@ -0,0 +1,32 @@
+using System.Text.Json;
+using OED.Api.Core.Interfaces.Services;
+using OED.Api.Core.Models.Eve;
+using StackExchange.Redis;
+
+namespace OED.Api.Infrastructure.Auth;
+
+public class SessionService(IConnectionMultiplexer redis) : ISessionService
+{
+    private readonly IDatabase _db = redis.GetDatabase();
+    private static readonly TimeSpan SessionTtl = TimeSpan.FromDays(7);
+
+    public async Task<string> CreateAsync(EveSession session)
+    {
+        var sessionId = Guid.NewGuid().ToString("N");
+        var json = JsonSerializer.Serialize(session);
+        await _db.StringSetAsync($"session:{sessionId}", json, SessionTtl);
+        return sessionId;
+    }
+
+    public async Task<EveSession?> GetAsync(string sessionId)
+    {
+        var json = await _db.StringGetAsync($"session:{sessionId}");
+        if (json.IsNullOrEmpty) return null;
+        return JsonSerializer.Deserialize<EveSession>((string)json!);
+    }
+
+    public async Task DeleteAsync(string sessionId)
+    {
+        await _db.KeyDeleteAsync($"session:{sessionId}");
+    }
+}