adding hidden basic asp.net core backend (#30)

Base functionality:

    DB
    email sending
    user registration & login
    storing new characters and reading them back

Notes:

    Functionality is "hidden" with no links pointing to it.
    Most pages are scaffolded and not reviewed at all :(
    local Dev db setup is pushed to git
    NO local email setup :(

Kemkas.Web/Services/Character/CharacterPersistenceService.cs

@@ -0,0 +1,47 @@
+using Kemkas.Web.Db;
+using Kemkas.Web.Db.Models;
+using Kemkas.Web.Services.Identity;
+using Microsoft.EntityFrameworkCore;
+
+namespace Kemkas.Web.Services.Character;
+
+public interface ICharacterPersistenceService
+{
+    public Task<Guid> StoreNewCharacter(V1Karakter karakter);
+    
+    public Task<V1Karakter?> GetCharacterById(Guid id);
+}
+
+public class CharacterPersistenceService(
+    ApplicationDbContext dbContext,
+    ICurrentUserService currentUserService
+    ) : ICharacterPersistenceService
+{
+
+    public async Task<Guid> StoreNewCharacter(V1Karakter karakter)
+    {
+        var currentUser = await currentUserService.GetCurrentUser();
+        karakter.OwnerUserId = currentUser?.Id;
+        karakter.Id = Guid.Empty;
+        dbContext.Karakterek.Add(karakter);
+        await dbContext.SaveChangesAsync();
+        return karakter.Id;
+    }
+
+    public async Task<V1Karakter?> GetCharacterById(Guid id)
+    {
+        var entity = await dbContext.Karakterek
+            .Include(x => x.KarakterKepzettsegek)
+            .Include(x => x.Szintlepesek)
+            .Include(x => x.Felszereles)
+            .FirstOrDefaultAsync(x => x.Id == id);
+        
+        if (entity?.OwnerUserId is null || entity.IsPublic)
+        {
+            return entity;
+        }
+        
+        var currentUser = await currentUserService.GetCurrentUser();
+        return entity.OwnerUserId == currentUser?.Id ? entity : null;
+    }
+}