CLI package is broken, build fails and tests are not passing

[fabiovincenzi]

Describe the bug

The @finos/git-proxy-cli workspace package is currently broken.
The CLI cannot be built from source and all 42 tests fail locally. The package has drifted out of sync with the main codebase over time, stale imports, missing exports, and CLI error handling no longer matching current server API responses.

To Reproduce

1. cd packages/git-proxy-cli && npm run build — build fails
2. cd ../.. && vitest --run --dir packages/git-proxy-cli/test — all 42 tests fail

Expected behavior
The CLI should build successfully and all tests should pass.