[Refactor] JWT auth filter

[nkcoder]

What

1. Specific Exception Handling: Catching specific JWT exceptions (ExpiredJwtException, MalformedJwtException, etc.) provides better debugging info and allows different handling strategies
2. Constants: Extract magic strings to constants - makes code self-documenting and prevents typos
3. Redundant Validation: isTokenExpired() is redundant when validateAccessToken() already throws on expiration
4. Stream Management: In servlet context, don't close response.getOutputStream() - let the container manage it
5. PII Protection: Log user IDs instead of emails; use DEBUG level for security events
6. Error Messages: Provide user-friendly messages without exposing internal details