fix(db): make PostgreSQL migrations atomic

[onmax]

PostgreSQL migrations are currently executed one statement at a time, with _hub_migrations updated only after every statement succeeds. A later failure can therefore leave committed DDL without a tracker row, while overlapping runners can both decide that the same migration is pending.

Fix

For PostgreSQL only, this PR:

• takes the same transaction-scoped advisory lock before tracker creation and migration application;
• rechecks _hub_migrations after acquiring the lock;
• executes the complete migration and tracker insert in one DO statement, so both succeed or both roll back.

Other dialects keep their existing behavior. Using one server-side statement also avoids requiring interactive transaction support from the driver.

Compatibility

This requires PL/pgSQL, which PostgreSQL installs by default. Commands PostgreSQL forbids inside transactions, such as CREATE INDEX CONCURRENTLY, fail without applying or recording the migration. Neon HTTP was not tested against a live endpoint; Drizzle forwards the wrapper through db.execute() as one query.

[vercel]

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[pkg-pr-new]

npm i https://pkg.pr.new/@nuxthub/core@921

commit: c2c59a5