fix(client): guard error response JSON parsing and map all non-2xx statuses

[amir-rezaei]

Description

This PR resolves issue #1146 by making error response handling in packages/taskdog-client/src/taskdog_client/base_client.py robust against non-JSON error payloads and unmapped HTTP status codes.

Details

• Guards JSON decoding on 404 responses with contextlib.suppress so HTML 404 pages (e.g. from reverse proxies) do not crash with raw JSONDecodeError.
• Preserves custom error details returned by the server on 401 response status codes.
• Maps all remaining non-2xx status codes (403, 405, 409, 429, 5xx) to ServerError(status_code, detail) instead of leaking unhandled httpx.HTTPStatusError exceptions.

[Kohei-Wada]

Thanks for the contribution, but CI is failing on this PR (Test (taskdog-client)), and no fix has been pushed.

Closing to keep the review queue actionable. Please feel free to reopen once:

• all required checks pass on your branch, and
• the change is covered by tests that pass locally (make check && make test).

A PR that fails its own package's test suite can't be reviewed on its merits, so please verify locally before opening.