fix(dashboard): guard sort param by dataset in widget table queries (#715)

## Summary

- Fix `queryWidgetTable` sending `sort` param for non-spans datasets
(errors/discover reject with 400 Bad Request)
- Enrich `ApiError` captures in `exceptionWhileRunningCommand` with
structured Sentry context (`status`, `endpoint`, `detail`) for better
diagnostics

Fixes CLI-129

## Details

`queryWidgetTimeseries` already correctly guarded the `sort` parameter
behind `dataset === "spans"` (lines 384-389), but `queryWidgetTable` was
passing `query?.orderby` unconditionally. When a dashboard has a table
or big_number widget with `error-events` or `discover` widget type and
the widget query has `orderby`, the events endpoint returns 400.

The `api_error` context on `Sentry.setContext()` ensures future ApiError
events include the endpoint URL and response detail, making it possible
to diagnose which API call failed without guessing from minified stack
traces.

Author: BYK