chore: replace Bazored.Toast with custom Toast component

[eduardosmaniotto]

Replace Blazored.Toast with a native Bootstrap 5 toast component

Summary

Removes the third-party Blazored.Toast NuGet dependency and replaces it with a toast implementation built on the Bootstrap 5 styles already present in the project. The new system follows the same service/container pattern as the existing ModalService/ModalContainer components and keeps the current API surface, so existing call sites compile unchanged.

Changes

• New toast components & services in Web/Shared:
  • IToastService + ToastService — scoped service with ShowSuccess / ShowInfo / ShowWarning / ShowError, manual close, and auto-dismiss.
  • ToastContainer — renders Bootstrap 5 toasts (level-based color/icon, slide-in, closing animation, dark-theme aware).
  • AddToasts() DI registration extension.
• Removed the Blazored.Toast package reference from Web/Shared, Web/AdminPanel, and the central Directory.Packages.props.
• Updated usages across the AdminPanel (Startup, WebApplicationExtensions, MainLayout, CreationPanel, pages) and host _Imports to use the new toast service/container; removed all Blazored @using directives.

Minor

• Fix new build warnings in EntityFrameworkContextBase.cs and 20260730194321_AddCastleSiege.cs

Sample