## Bug Description
When reordering stages in the Kanban board, the frontend fires all
viewGroup update mutations concurrently via Promise.all, causing race
conditions in the workspace migration runner's cache invalidation,
database contention, and a thundering herd effect that stalls the
server.
## Changes
Changed `usePerformViewGroupAPIPersist` to execute viewGroup update
mutations sequentially instead of concurrently. The `Promise.all`
pattern fired all N mutations simultaneously, each triggering a full
workspace migration runner pipeline (transaction + cache invalidation).
The sequential `for...of` loop ensures each mutation completes
(including its cache invalidation) before the next begins, eliminating
the race condition.
## Related Issue
Fixes#18865
## Testing
This fix addresses the root cause identified in the Sonarly analysis on
the issue. The concurrent mutation pattern was causing:
- PostgreSQL row-level lock contention on viewGroup rows
- Cache thundering herd from repeated invalidation/recomputation cycles
- Server stalls requiring container restarts
The sequential approach ensures proper ordering and prevents these race
conditions.
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Co-authored-by: Rayan <rayan@example.com>
Co-authored-by: Charles Bochet <charles@twenty.com>
