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/categories.go

@@ -119,4 +119,4 @@ func generateSlug(name string) string {
 		}
 	}
 	return result
-}
+}