> [!NOTE]
> Adds a configurable concurrency for link migrations (CLI/commands), forces concurrency=1 when pgstream is detected, and ignores duplicate link-table inserts.
>
> - **CLI**
> - Add `--concurrency` option to `db:migrate` and `db:sync-links`.
> - **Medusa commands**
> - `migrate` and `sync-links` accept `concurrency`; set `DB_MIGRATION_CONCURRENCY` and force `1` when `pgstream` schema exists via new `isPgstreamEnabled`.
> - **Link Modules (migrations)**
> - Execute plan actions with `executeWithConcurrency` using `DB_MIGRATION_CONCURRENCY`.
> - Make link-table tracking inserts idempotent with `ON CONFLICT DO NOTHING` (including bulk/upsert and per-create).
>
> <sup>Written by [Cursor Bugbot](https://cursor.com/dashboard?tab=bugbot) for commit 07432293c8fe8de30b07920fa47823b9081edacc. This will update automatically on new commits. Configure [here](https://cursor.com/dashboard?tab=bugbot).</sup>
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