auth: add safari-auth plugin for iOS OAuth (#433)

* auth: add safari-auth plugin for iOS OAuth

* fix: temporarily disable email auth provider for iOS

apps/readest-app/src-tauri/plugins/tauri-plugin-safari-auth/src/lib.rs

@@ -0,0 +1,48 @@
+use tauri::{
+    plugin::{Builder, TauriPlugin},
+    Manager, Runtime,
+};
+
+pub use models::*;
+
+#[cfg(desktop)]
+mod desktop;
+#[cfg(mobile)]
+mod mobile;
+
+mod commands;
+mod error;
+mod models;
+
+pub use error::{Error, Result};
+
+#[cfg(desktop)]
+use desktop::SafariAuth;
+#[cfg(mobile)]
+use mobile::SafariAuth;
+
+/// Extensions to [`tauri::App`], [`tauri::AppHandle`] and [`tauri::Window`] to access the safari-auth APIs.
+pub trait SafariAuthExt<R: Runtime> {
+    fn safari_auth(&self) -> &SafariAuth<R>;
+}
+
+impl<R: Runtime, T: Manager<R>> crate::SafariAuthExt<R> for T {
+    fn safari_auth(&self) -> &SafariAuth<R> {
+        self.state::<SafariAuth<R>>().inner()
+    }
+}
+
+/// Initializes the plugin.
+pub fn init<R: Runtime>() -> TauriPlugin<R> {
+    Builder::new("safari-auth")
+        .invoke_handler(tauri::generate_handler![commands::auth_with_safari])
+        .setup(|app, api| {
+            #[cfg(mobile)]
+            let safari_auth = mobile::init(app, api)?;
+            #[cfg(desktop)]
+            let safari_auth = desktop::init(app, api)?;
+            app.manage(safari_auth);
+            Ok(())
+        })
+        .build()
+}