fix: more locations with .designer.ipynb extension stripping

[artchen-db]

Summary

Lakeflow Designer notebooks are stored as DESIGNER_FILE objects with a compound .designer.ipynb extension. Several CLI sites stripped notebook extensions with path.Ext + TrimSuffix, removing only the trailing .ipynb and leaving an orphaned .designer — a path that no longer round-trips on deploy/import. This routes them through the existing notebook.StripExtension helper, which preserves the suffix. (Originally reported for bundle generate of a job referencing a Designer notebook.)

Key changes

• bundle/generate/downloader.go — the reported bug; preserve the suffix and download Designer files as Jupyter (get-status reports no export format for them).
• libs/notebook/ext.go — add ObjectTypeDesignerFile + FixedExportFormat(objectType), so the format override is keyed generically on object type rather than a designer-specific check.
• libs/sync/snapshot_state.go — sync otherwise tracked Designer notebooks at the wrong remote name, inconsistent with translate_paths.
• cmd/workspace/workspace/import_dir.go — logged remote path for imported Designer notebooks.

Notes

• Audited the read/export paths (export_dir.go, configsync/resolve.go, filer extensions client, detect.go): already correct — Designer objects keep their full name and aren't NOTEBOOK-typed, so they round-trip as regular files.
• Tests: TestFixedExportFormat, TestDownloader_MarkTasksForDownload_DesignerNotebook, a sync fixture, and an end-to-end acceptance/bundle/generate/designer_job/ test.

[github-actions]

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Inputs:

• PR number: 5656
• Commit SHA: da60eeb9a91e130cba0b902496ee5313286da186

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[github-actions]

Approval status: pending

/acceptance/bundle/ - needs approval

7 files changed
Suggested: @pietern
Also eligible: @denik, @shreyas-goenka, @andrewnester, @anton-107, @janniklasrose, @lennartkats-db

/bundle/ - needs approval

Files: bundle/generate/downloader.go, bundle/generate/downloader_test.go
Suggested: @pietern
Also eligible: @denik, @shreyas-goenka, @andrewnester, @anton-107, @janniklasrose, @lennartkats-db

/libs/sync/ - needs approval

Files: libs/sync/snapshot_state.go, libs/sync/snapshot_state_test.go, libs/sync/testdata/sync-fileset/designer-nb.designer.ipynb
Suggested: @simonfaltum
Also eligible: @Divyansh-db, @renaudhartert-db, @hectorcast-db, @parthban-db, @tanmay-db, @tejaskochar-db, @mihaimitrea-db, @chrisst, @rauchy

General files (require maintainer)

Files: cmd/workspace/workspace/import_dir.go, libs/notebook/ext.go, libs/notebook/ext_test.go
Based on git history:

• @pietern -- recent work in libs/sync/, bundle/generate/, cmd/workspace/workspace/

_{Any maintainer (@andrewnester, @anton-107, @denik, @pietern, @shreyas-goenka, @simonfaltum, @renaudhartert-db) can approve all areas.
See OWNERS for ownership rules.}