## Problem
Syncing workflowVersion to core fails with `duplicate key value violates
unique constraint "IDX_WORKFLOW_VERSION_ONE_ACTIVE_PER_WORKFLOW"`. The
sync's `INSERT ... ON CONFLICT ("id")` only dedupes the primary key — it
can't dedupe `IDX_WORKFLOW_VERSION_ONE_ACTIVE_PER_WORKFLOW`
(`(workspaceId, workflowId) WHERE status='ACTIVE'`). When a leftover
ACTIVE core row exists for a `(workspaceId, workflowId)` with a stale id
(accumulated across the sync's earlier id schemes), inserting the new
active row collides, and the per-id purge misses it.
## Fix
Rewrite the 2-22 `backfill-workflow-version-core-links` command as a
**full rebuild**. Per workspace, in one raw-SQL transaction (core and
workspace schemas are the same database):
1. `DELETE` all `core.workflowVersion` for the workspace — clears every
stale/leftover row.
2. Insert a fresh own-id core row for **every** workspace version.
3. `UPDATE` `coreWorkflowVersionId` on **every** workspace record to its
new core id.
Because it wipes first and re-links all records, leftover ACTIVE rows
can't collide and no record is left pointing at a deleted core row — so
the dual-write's `linked → update` path stays correct afterward.
## Test (local)
Fresh reset, and a reproduced dirty state (leftover ACTIVE core row with
a stale id + a stale link + an unlinked record):
- rebuild runs with no `ONE_ACTIVE` / duplicate-key error,
- leftover wiped, stale link replaced, every record re-linked to a fresh
own-id row,
- 0 dangling/unlinked, no duplicate core rows, exactly one ACTIVE core
version per workflow.
Typecheck + lint + oxfmt clean.
## Note
The 2-20 `backfill-workflow-version-to-core` can still log per-workspace
conflicts on already-dirty instances, but they're non-fatal (the
iterator continues) and this rebuild corrects the end state. The
dual-write (`upsertToCore`) is unchanged and works on the clean data
this produces.
Thomas Trompette
f8b7ecf680