Add build/job status commands for transform datasets

[anjor]

Problem

There is no CLI command to check the build/job status of a dataset's transforms. When a transform build fails, users have to go to the Foundry web UI to see the error.

Expected Behavior

Something like:

pltr dataset builds <rid> --limit 5
pltr dataset build-log <rid>  # or <build-rid>

Should show:

• Build status (running/succeeded/failed)
• Error messages for failed builds
• Build duration, timestamps

Context

Foundry exposes build status through internal APIs (jemma, build2, stemma checks). The CLI should wrap these to provide a unified interface for checking transform build status.

API Endpoints to Investigate

• /stemma/api/repos/{repoRid}/checks — returns CI check status per branch (confirmed working)
• /jemma/api/ — job/build management (needs exploration for the right endpoints)
• The Foundry web UI shows build logs somewhere — those APIs need to be discovered and wrapped

Use Case

AI agents and CLI users need to debug transform failures without switching to the browser.