test(cli): cover cloud reportApiError hint cascade (#1131)

reportApiError centralizes the HyperframesApiError -> Error -> String
reporting cascade for the cloud subverbs, including the curated
ERROR_CODE_HINTS table and its priority order (code-specific hint >
caller suggestion > bare code label > no third line). That priority
logic was previously untested; the module comment notes a past
regression where hyperframes_render_not_found was unreachable from
get/delete.

Add errors.test.ts covering: 404 + notFound short-circuit, known-code
hint, hint-wins-over-suggestion priority, suggestion fallback, bare
code label, no-third-line, extraHints merge and override, plain Error,
and non-Error stringification. Mocks errorBox and process.exit
following the sibling cloud/parsing.test.ts pattern.

Co-authored-by: Carlos Alcaraz <193642530+calcarazgre646@users.noreply.github.com>