## Summary
Adds `upgrade:1-21:fix-message-thread-view-and-label-identifier` to
retroactively apply two messageThread changes from #19351 that never
propagated to existing workspaces (because
`synchronizeTwentyStandardApplicationOrThrow` only runs at workspace
creation):
1. **`allMessageThreads` view fields**: delete-and-recreate all view
fields for the standard view from the current twenty-standard
definition, which adds the new `subject` and `updatedAt` columns. Same
pattern as the FIELDS_WIDGET sync in
`1-21-workspace-command-1775500005000-backfill-page-layouts-and-fields-widget-view-fields`.
2. **`messageThread.labelIdentifierFieldMetadataId`**: repointed to the
`subject` field via `validateBuildAndRunWorkspaceMigration`. The
migration runner already resolves
`labelIdentifierFieldMetadataUniversalIdentifier` → id in
`update-object-action-handler`, so this goes through the standard flow
and properly invalidates caches.
Both fixes share a single `validateBuildAndRunWorkspaceMigration` call
(one `viewField` op, one `objectMetadata` update op). Idempotent — skips
if nothing to do.
Depends on `upgrade:1-21:backfill-message-thread-subject` having run
first (the label identifier fix needs the `subject` field to exist; it
logs a warning and skips that part otherwise).
## Test plan
- [ ] Legacy workspace: run \`backfill-message-thread-subject\`, then
this command, then verify:
- the \`allMessageThreads\` view shows the new \`subject\` and
\`updatedAt\` columns
- messageThread records display their \`subject\` as the record label
- [ ] Re-run the command: no-op, logs \`Nothing to fix\`
- [ ] \`--dry-run\` logs planned changes without applying them
🤖 Generated with [Claude Code](https://claude.com/claude-code)
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Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>
Félix Malfait
9bdef449e6