feat(udt-011): T400.10 — inject TimeProvider into all Application handlers

All command handlers that call domain mutators now inject TimeProvider
via constructor and use _timeProvider.GetUtcNow().UtcDateTime as the
explicit 'now' argument. Replaces previous direct DateTime.UtcNow usage.

src/api/SIGCM2.Application/Auth/Login/LoginCommandHandler.cs

@@ -22,6 +22,7 @@ public sealed class LoginCommandHandler : ICommandHandler<LoginCommand, LoginRes
     private readonly IRolPermisoRepository _rolPermisoRepository;
     private readonly ISecurityEventLogger _security;
     private readonly ILogger<LoginCommandHandler> _logger;
+    private readonly TimeProvider _timeProvider;
 
     public LoginCommandHandler(
         IUsuarioRepository repository,
@@ -33,7 +34,8 @@ public sealed class LoginCommandHandler : ICommandHandler<LoginCommand, LoginRes
         AuthOptions authOptions,
         IRolPermisoRepository rolPermisoRepository,
         ISecurityEventLogger security,
-        ILogger<LoginCommandHandler> logger)
+        ILogger<LoginCommandHandler> logger,
+        TimeProvider timeProvider)
     {
         _repository = repository;
         _hasher = hasher;
@@ -45,6 +47,7 @@ public sealed class LoginCommandHandler : ICommandHandler<LoginCommand, LoginRes
         _rolPermisoRepository = rolPermisoRepository;
         _security = security;
         _logger = logger;
+        _timeProvider = timeProvider;
     }
 
     public async Task<LoginResponseDto> Handle(LoginCommand command)
@@ -81,7 +84,7 @@ public sealed class LoginCommandHandler : ICommandHandler<LoginCommand, LoginRes
         // Generate and persist refresh token — only the hash hits the DB
         var rawRefresh = _refreshGenerator.Generate();
         var hash = TokenHasher.Sha256Base64Url(rawRefresh);
-        var now = DateTime.UtcNow;
+        var now = _timeProvider.GetUtcNow().UtcDateTime;
         var ttl = TimeSpan.FromDays(_authOptions.RefreshTokenDays);
         var entity = RefreshToken.IssueForNewFamily(
             usuario.Id, hash, now, ttl,