feat(i18n): add localized desktop UI

Refs #17

src-tauri/src/ipc.rs

@@ -6,6 +6,10 @@ fn default_speed_limit_unit() -> String {
     "MB/s".to_string()
 }
 
+fn default_language_preference() -> String {
+    "system".to_string()
+}
+
 #[derive(Clone, Copy, Debug, Serialize, Deserialize, TS)]
 #[serde(rename_all = "lowercase")]
 #[ts(export, export_to = "../../src/bindings/")]
@@ -257,6 +261,8 @@ pub struct SchedulerSettings {
 #[ts(export, export_to = "../../src/bindings/")]
 pub struct PersistedSettings {
     pub theme: Theme,
+    #[serde(default = "default_language_preference")]
+    pub language: String,
     pub base_download_folder: String,
     pub category_subfolders_enabled: bool,
     pub category_subfolders: HashMap<String, String>,

src-tauri/src/settings.rs

@@ -192,6 +192,11 @@ fn sanitize_persisted_setting_values(state: &mut Value) {
         "theme",
         &["system", "light", "dark", "dracula", "nord"],
     );
+    sanitize_allowed_string(
+        state,
+        "language",
+        &["system", "en", "zh-CN", "he", "fa", "uk", "ru"],
+    );
     sanitize_allowed_string(state, "appFontSize", &["small", "standard", "large"]);
     sanitize_allowed_string(state, "listRowDensity", &["compact", "standard", "relaxed"]);
     sanitize_allowed_string(state, "activeSettingsTab", &[
@@ -410,6 +415,7 @@ fn derived_location_path(base: &str, subfolder: &str) -> String {
 fn default_settings() -> PersistedSettings {
     PersistedSettings {
         theme: Theme::System,
+        language: "system".to_string(),
         base_download_folder: "~/Downloads".to_string(),
         category_subfolders_enabled: true,
         category_subfolders: default_category_subfolders(),