fix(auth): preserve session on reload and correct 401 redirect flow

- Save PKCE params to sessionStorage.redirectState on 401 instead of overwriting tokenSet

- Persist userData in sessionStorage after OIDC callback for later hydration

- Hydrate Redux (tokens + userData) from sessionStorage on app start to avoid forced re-login

- Keep SPA single route '/' behavior unchanged; only improves auth robustness

Files: src/utils/apiUtils.ts, src/features/User/LoginCallback.tsx, src/features/User/HandleLogin.tsx

src/utils/apiUtils.ts

@@ -23,7 +23,7 @@ export const api = ky.extend({
           const loginurl = await Auth();
 
           sessionStorage.setItem(
-            "tokenSet",
+            "redirectState",
             JSON.stringify({
               code_verifier: loginurl.code_verifier,
               state: loginurl.state,