Refactor dataset detail page: extract Data Card and Versions & Files tabs

[rbelavadi]

Task Summary

Summary

Sub-issue of #6394: splits the remaining content on the dataset detail page into two tabs: Data Card (read-only dataset overview) and Versions & Files (existing file browser and version management, relocated unchanged). This is the second of three sub-issues under the tab-based layout refactor; #6395 (Settings) covered the first.

Scope

Versions & Files: pure relocation. The existing file browser, version selector, file preview, and upload widget move into this tab verbatim, with no logic changes.

Data Card — read-only overview, split into two cards:

• A wide card containing the dataset description (moved out of the page header, which currently duplicates it) plus a schema preview for the latest version's primary file
• A narrower card containing key facts: Created date, Last updated, Latest version file name, and version size

Task Type

• Refactor / Cleanup
• DevOps / Deployment / CI
• Testing / QA
• Documentation
• Performance
• Other

[rbelavadi]

/parent-issue #6394

[rbelavadi]

/take

[github-actions]

👋 Thanks for opening this issue, @rbelavadi!

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