Update Refresh Token on proposal API Logic to Expire Only Upon Use

## Description
Modify the **refresh token** on proposal API behavior so that it **only expires once it has been used** or **lifespan of token is exceeded**.
This ensures better session continuity and avoids premature expiration due to inactivity or background operations.

## Acceptance Criteria
- [ ] Refresh token is marked as expired **only after it is successfully used** to obtain a new access token.
- [ ] Unused refresh tokens remain valid until explicitly used or revoked.
- [ ] Behavior is consistent across login, token refresh, and logout flows.