feat: implement JWT refresh token mechanism and improve auth

- Add refresh token support with 30-day expiry
- Implement automatic token rotation on refresh
- Add new endpoints: /auth/refresh, /auth/revoke-token, /auth/revoke-all-tokens
- Reduce access token lifetime to 1 hour for better security
- Store refresh tokens in user document with metadata
- Add support for token cleanup and management
- Update login flow to return both access and refresh tokens
- Maintain backward compatibility with existing auth methods

pkg/handlers/auth_helpers.go

@@ -4,4 +4,4 @@ import (
 	"github.com/google/uuid"
 )
 
-func uuidNew() string { return uuid.New().String() }
+func uuidNew() string { return uuid.New().String() }