feat: Implement a customizable dashboard with user preferences and a dynamic widget system.

src/backend/Zentral.Infrastructure/Data/ZentralDbContext.cs

@@ -34,6 +34,7 @@ public class ZentralDbContext : DbContext
     public DbSet<EventoDegustazione> EventiDegustazioni => Set<EventoDegustazione>();
     public DbSet<Configurazione> Configurazioni => Set<Configurazione>();
     public DbSet<Utente> Utenti => Set<Utente>();
+    public DbSet<UserDashboardPreference> UserDashboardPreferences => Set<UserDashboardPreference>();
 
     // Report entities
     public DbSet<ReportTemplate> ReportTemplates => Set<ReportTemplate>();
@@ -311,6 +312,16 @@ public class ZentralDbContext : DbContext
             entity.HasIndex(e => e.Username).IsUnique();
         });
 
+        // UserDashboardPreference
+        modelBuilder.Entity<UserDashboardPreference>(entity =>
+        {
+            entity.HasIndex(e => e.UtenteId).IsUnique();
+            entity.HasOne(e => e.Utente)
+                .WithOne()
+                .HasForeignKey<UserDashboardPreference>(e => e.UtenteId)
+                .OnDelete(DeleteBehavior.Cascade);
+        });
+
         // ReportTemplate
         modelBuilder.Entity<ReportTemplate>(entity =>
         {