✅ (tests): Adapta la suite al nuevo framework web

- Sustituye `service::test::*` por `web::test::*` (migración de actix-web a
  axum).
- Extrae `setup()` en los módulos que sólo renderizan componentes,
  evitando levantar un router completo en cada test.
- Elimina los `env::set_var("PAGETOP_RUN_MODE", "test")` manuales, ya
  cubiertos por la *feature* `testing`.

tests/component_poweredby.rs

@@ -1,8 +1,16 @@
 use pagetop::prelude::*;
 
+/// Inicializa PageTop (locale, extensiones…) una sola vez para toda la suite.
+///
+/// Los tests de este módulo renderizan componentes directamente con `Context::default()`, por lo
+/// que sólo necesitan el subsistema de localización y las extensiones registradas, no un router.
+fn setup() {
+    let _ = Application::new();
+}
+
 #[pagetop::test]
 async fn poweredby_default_shows_only_pagetop_recognition() {
-    let _app = service::test::init_service(Application::new().test()).await;
+    setup();
 
     let mut p = PoweredBy::default();
     let html = p.render(&mut Context::default());
@@ -16,7 +24,7 @@ async fn poweredby_default_shows_only_pagetop_recognition() {
 
 #[pagetop::test]
 async fn poweredby_new_includes_current_year_and_app_name() {
-    let _app = service::test::init_service(Application::new().test()).await;
+    setup();
 
     let mut p = PoweredBy::new();
     let html = p.render(&mut Context::default());
@@ -40,7 +48,7 @@ async fn poweredby_new_includes_current_year_and_app_name() {
 
 #[pagetop::test]
 async fn poweredby_with_copyright_overrides_text() {
-    let _app = service::test::init_service(Application::new().test()).await;
+    setup();
 
     let custom = "2001 © FooBar Inc.";
     let mut p = PoweredBy::default().with_copyright(Some(custom));
@@ -52,7 +60,7 @@ async fn poweredby_with_copyright_overrides_text() {
 
 #[pagetop::test]
 async fn poweredby_with_copyright_none_hides_text() {
-    let _app = service::test::init_service(Application::new().test()).await;
+    setup();
 
     let mut p = PoweredBy::new().with_copyright(None::<String>);
     let html = p.render(&mut Context::default());
@@ -64,7 +72,7 @@ async fn poweredby_with_copyright_none_hides_text() {
 
 #[pagetop::test]
 async fn poweredby_link_points_to_crates_io() {
-    let _app = service::test::init_service(Application::new().test()).await;
+    setup();
 
     let mut p = PoweredBy::default();
     let html = p.render(&mut Context::default());
@@ -77,7 +85,7 @@ async fn poweredby_link_points_to_crates_io() {
 
 #[pagetop::test]
 async fn poweredby_getter_reflects_internal_state() {
-    let _app = service::test::init_service(Application::new().test()).await;
+    setup();
 
     // Por defecto no hay copyright.
     let p0 = PoweredBy::default();