feat: saveToken plugin for app groups on iOS

This will allow the share extension to access the Bearer token to send
images to the backend.

frontend/src/ProtectedRoute.tsx

@@ -1,6 +1,7 @@
 import { type Component, type JSX, Show } from "solid-js";
 import { jwtDecode } from "jwt-decode";
 import { Navigate } from "@solidjs/router";
+import { saveToken } from "tauri-plugin-ios-shared-token-api";
 
 export const isTokenValid = (): boolean => {
     const token = localStorage.getItem("access");
@@ -22,6 +23,15 @@ export const ProtectedRoute: Component<{ children?: JSX.Element }> = (
 ) => {
     const isValid = isTokenValid();
 
+    if (isValid) {
+        const token = localStorage.getItem("access");
+        if (token == null) {
+            throw new Error("unreachable");
+        }
+
+        saveToken(token);
+    }
+
     return (
         <Show when={isValid} fallback={<Navigate href="/login" />}>
             {props.children}