fix(web): prevent redirect loop on Continue as default dev user

GRO-264: The "Continue as default dev user" button on /login clears
dev-user from localStorage then navigates to /admin, but App.tsx's
auth guard immediately redirects back to /login because getDevUser()
is null. Fix by setting a dev-login-skipped flag that App.tsx checks
to allow through-navigation after explicit skip.

Co-Authored-By: Paperclip <noreply@paperclip.ing>

apps/web/src/App.tsx

@@ -245,7 +245,8 @@ export function App() {
   }
 
   // Dev mode: use dev login selector (no setup check needed in dev mode)
-  if (authDisabled && !getDevUser()) {
+  // Skip redirect if user explicitly chose "continue as default dev user" (dev-login-skipped flag)
+  if (authDisabled && !getDevUser() && !localStorage.getItem("dev-login-skipped")) {
     return <Navigate to="/login" replace />;
   }