Improve LakeFS error handling with centralized exception wrapper #4176
Description
Feature Summary
Add centralized error handling for LakeFS API calls to properly convert io.lakefs.clients.sdk.ApiException to appropriate HTTP exceptions with meaningful error messages visible to frontend.
Problem
Currently, LakeFS API exceptions are not handled consistently across the codebase (e.g., DatasetResource).
In multipart upload flows, some failures often surface as DataAccessException without the original LakeFS error context, which makes issues hard to reproduce and debug from both backend logs and frontend responses.
Proposed Solution or Design
Add handleLakeFSException to convert LakeFS ApiException to JAX-RS exceptions (400, 401, 403, 404, 409, 500, etc.)
Impact / Priority
(P2)Medium – useful enhancement
Affected Area
No response