- Add isTokenValid() to decode JWT and check exp claim
- Refresh tokens 60 seconds before expiry (buffer)
- Auto-fetch fresh token via SSO-Link when cached token expires
- Clear invalid sessions when refresh fails
- Prevents "exp claim timestamp check failed" errors
JWT tokens from mana-core-auth expire after 15 minutes, but sessions
were cached for 7 days. Now tokens are transparently refreshed when
they expire, keeping users authenticated.
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>