feat(config): turn the Form View on by default

[yangzhang75]

Task Summary

Turn the Form View on by default: flip form-view-enabled in gui.conf from false to true, with the GuiConfigSpec assertion updated to match. The closing item of the Form View stack (parent #8011): every piece has landed behind the flag (#8013 .. #8028), so the default can move. A deployment that wants it off sets GUI_WORKFLOW_WORKSPACE_FORM_VIEW_ENABLED=false, which the config already reads.

Split out of #8028 so the rollout is its own reviewable step (PR #8528).

Task Type

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

[github-actions]

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[yangzhang75]

/parent-issue: #8011