fix(client): prefer localStorage token over memory in token mode

[markwylde]

Summary

• Fix refreshSession token mode refresh-token selection so it prefers the latest localStorage value when tokenStorage is configured as localStorage.
• Preserve current fallback behavior for memory configuration by continuing to prefer the in-memory token.
• Add regression test for refresh-token preference across sequential refreshSession calls when storage values diverge.

Testing

• npm run tidy
• npm run build