Add token refresh to keycloak client

[veenupunyani]

PR Summary

• Added Keycloak access-token refresh while the user stays signed in.
• Scheduled updateToken about 30 seconds before the access token expires (~5 min lifespan).
• Routed protected API calls through getAccessToken so the token is refreshed before use.
• Cleared the auth session when refresh failed or the refresh token was bad/missing.

Testing Steps

1. Sign in -> stay on the app ~5+ minutes -> still signed in (access token refreshed in sessionstorage, check in dev tools)
2. Break or clear the refresh token, you can change the value of refresh token in dev tool to corrupt it -> session clears and user is treated as signed out
3. Sign out -> refresh timer stops and does not keep running, clears out tokens.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[chrsamp]

This is great, nice PR! Thank you @veenupunyani. Token refresh tested in dev + working.