fix(webapp): also clear stale auth errors stored by the previous session format

Sessions written before the flash fix stored auth:error with session.set, which get() does not auto-clear. Unset it explicitly after reading so those sessions heal on their next visit instead of carrying the stale error until the cookie expires.

Author: samejr

apps/webapp/app/routes/login._index/route.tsx

@@ -121,6 +121,11 @@ export async function loader({ request }: LoaderFunctionArgs) {
   // attempts look like they failed.
   const userSession = await getUserSession(request);
   const error = userSession.get("auth:error");
+  // get() only auto-clears flash-stored values. Sessions written before this
+  // fix stored the error with set(), which survives get() + commit — unset it
+  // explicitly so those sessions heal too instead of showing the stale error
+  // until the cookie's one-year maxAge runs out.
+  userSession.unset("auth:error");
 
   let authError: string | undefined;
   if (error) {

apps/webapp/app/routes/login.magic/route.tsx

@@ -91,6 +91,9 @@ export async function loader({ request }: LoaderFunctionArgs) {
   }
 
   const error = session.get("auth:error");
+  // Same migration hygiene as /login: pre-fix sessions stored this with
+  // set(), which get() doesn't clear — unset so the commit below removes it.
+  session.unset("auth:error");
 
   const redirectTo = sanitized === "/" ? null : sanitized;
   const headers = new Headers();