✨ Añade soporte a temas en la API de extensiones

- Incluye una opción de configuración para definir el tema por defecto.
- Añade un tema básico predeterminado.

src/core/theme/all.rs

@@ -0,0 +1,31 @@
+use crate::core::theme::ThemeRef;
+use crate::global;
+
+use std::sync::{LazyLock, RwLock};
+
+// TEMAS *******************************************************************************************
+
+pub static THEMES: LazyLock<RwLock<Vec<ThemeRef>>> = LazyLock::new(|| RwLock::new(Vec::new()));
+
+// TEMA PREDETERMINADO *****************************************************************************
+
+pub static DEFAULT_THEME: LazyLock<ThemeRef> =
+    LazyLock::new(|| match theme_by_short_name(&global::SETTINGS.app.theme) {
+        Some(theme) => theme,
+        None => &crate::base::theme::Basic,
+    });
+
+// TEMA POR NOMBRE *********************************************************************************
+
+pub fn theme_by_short_name(short_name: impl AsRef<str>) -> Option<ThemeRef> {
+    let short_name = short_name.as_ref().to_lowercase();
+    match THEMES
+        .read()
+        .unwrap()
+        .iter()
+        .find(|t| t.short_name().to_lowercase() == short_name)
+    {
+        Some(theme) => Some(*theme),
+        _ => None,
+    }
+}