Token now expires after 12h

[Spampa]

This pull request extends the authentication token and session expiry from 6 hours to 12 hours across both the backend and frontend. It also improves how the frontend parses and synchronizes token expiry, ensuring consistency between the backend JWT and frontend session handling.

Backend expiry updates:

• Increased JWT expiry from 6 hours to 12 hours in the TokenService (apps/backend/src/modules/auth/token.service.ts).
• Updated the mysagra_token cookie's maxAge to 12 hours in the AuthController (apps/backend/src/modules/auth/auth.controller.ts).

Frontend expiry handling and synchronization:

• Added a parseTokenExpiry function in auth.ts to extract the expiry from the JWT and use it for setting the cookie's maxAge, ensuring the frontend cookie matches the backend token's expiry (apps/frontend/lib/auth.ts). [1] [2]
• Updated the session and cookie maxAge values to 12 hours to match the backend, and propagated the token expiry throughout the authentication flow (apps/frontend/lib/auth.ts). [1] [2]
• Ensured the token expiry (exp) is included in the JWT and session objects for consistent expiry tracking on the frontend (apps/frontend/lib/auth.ts). [1] [2]