## workflowVersion -> core, Phase A
Follows #21674 (Phase 0, merged). Base: `main`.
Populates core `workflowVersion` and keeps it in sync with the workspace
object, so a later phase can switch reads to core. Reads stay on the
workspace object in this PR.
### 1. Backfill (upgrade command)
`BackfillWorkflowVersionToCoreCommand`, a
`@RegisteredWorkspaceCommand('2.20.0', ...)`. Per workspace, reads all
workspace `workflowVersion` records and upserts them into core,
preserving ids (idempotent), dry-run aware.
### 2. Dual-write (always on, not flag-gated)
`WorkflowVersionCoreDualWriteListener` hooks
`@OnDatabaseBatchEvent('workflowVersion', CREATED/UPDATED/DELETED)`
(same mechanism as the existing workflow-version status listener) and
mirrors every mutation into core. Sync failures are logged, never break
the user's write; drift is repaired by re-running the backfill command.
Dual-write is deliberately not behind a flag: reading from core (next
phase) is only safe if core has been continuously in sync since the
backfill. An always-on mirror makes "core is fresh" an invariant, so the
read switch becomes a plain flag flip. The cost is one extra upsert on
infrequent workflowVersion writes.
`IS_WORKFLOW_VERSION_IN_CORE_ENABLED` is reserved for the read switch
(Phase B): dispatch from the `workflowAutomatedTriggerMaps` cache,
runner and builder reading trigger/steps from core. Until then it gates
nothing.
Both the backfill and the listener go through a single
`WorkflowVersionCoreSyncService` (`upsertToCore`/`deleteFromCore`): the
workspace-to-core mapping (`trigger` -> `triggers[]`, plus `steps`,
`status`, `workflowId`) and `workflowAutomatedTriggerMaps` invalidation
live in one place.
### Rollout plan (following phases)
- **B, read switch (flag per workspace):** reads move to core; writes
keep flowing workspace -> listener -> core. Rollback = flip the flag
back, workspace never stopped being source of truth.
- **C, contract (code change):** write paths write trigger/steps to core
directly; workspace `workflowVersion` stays as a thin shell
(nav/relations/search) but drops the trigger/steps columns; listener and
flag removed.
### Not in this PR
- Reconciliation tooling beyond re-running the backfill.
- The read switch (Phase B).
Thomas Trompette
ca90a9358f