Alinear BD local con esquema de produccion, login offline y publicacion portable

- Modelos renombrados para coincidir con columnas de MariaDB (ApPaterno/ApMaterno, HoraSalida, FechaFin, IdAsistenciaProfesor)
- Agregado campo IdAlumno a DetalleContrato
- Seed data con IDs reales de produccion (16451, 16493, profesor 15668563-1)
- Login offline: solo valida RUT contra BD local, sin contraseña
- ConnectivityService: checkea internet al inicio, bloquea si hay conexion
- ViewLocator corregido: busca tipos en todos los ensamblados
- Todos los ViewModels heredan de ViewModelBase
- Publicacion self-contained para win-x64, linux-x64, osx-x64, osx-arm64
- Agregado .gitignore, removidos bin/obj/publish del tracking

Asistencia/ViewLocator.cs

@@ -1,14 +1,12 @@
 using System;
 using System.Diagnostics.CodeAnalysis;
+using System.Linq;
 using Avalonia.Controls;
 using Avalonia.Controls.Templates;
 using Asistencia.ViewModels;
 
 namespace Asistencia;
 
-/// <summary>
-/// Given a view model, returns the corresponding view if possible.
-/// </summary>
 [RequiresUnreferencedCode(
     "Default implementation of ViewLocator involves reflection which may be trimmed away.",
     Url = "https://docs.avaloniaui.net/docs/concepts/view-locator")]
@@ -18,15 +16,17 @@ public class ViewLocator : IDataTemplate
     {
         if (param is null)
             return null;
-        
+
         var name = param.GetType().FullName!.Replace("ViewModel", "View", StringComparison.Ordinal);
-        var type = Type.GetType(name);
+        var type = AppDomain.CurrentDomain.GetAssemblies()
+            .Select(a => a.GetType(name))
+            .FirstOrDefault(t => t != null);
 
         if (type != null)
         {
             return (Control)Activator.CreateInstance(type)!;
         }
-        
+
         return new TextBlock { Text = "Not Found: " + name };
     }