docs(aurora-dsql): update SELECT FOR UPDATE Kiro guidance

[mchenjh]

Summary

Mirror the canonical Aurora DSQL SELECT FOR UPDATE guidance in the Kiro Power. This is part of a coordinated rollout; sibling PR links will be added after all PRs are opened.

Changes

• Remove obsolete all-primary-key equality and single-table restrictions.
• Document commit-time OCC behavior, supported lock clauses, SQLSTATE 40001 retries, and 10 MiB locked-primary-key accounting.
• Correct framework guidance and routing for locking questions.
• Add a changelog entry.

User experience

Kiro now recommends supported SELECT FOR UPDATE query shapes and whole-transaction retry behavior without carrying the pre-GA restrictions.

Checklist

• I have reviewed the contributing guidelines
• I have performed a self-review of this change
• Changes have been tested
• Changes are documented

Is this a breaking change? N

RFC issue number: N/A

Acknowledgment

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of the project license.

Related rollout PRs

• Canonical agent guidance: docs(dsql): update SELECT FOR UPDATE guidance and evals agent-plugins#271
• Kiro Power mirror: docs(aurora-dsql): update SELECT FOR UPDATE Kiro guidance #4607
• Flyway compatibility cleanup: Remove obsolete Aurora DSQL table-lock override flyway/flyway-community-db-support#149
• ORM adapters: Update Hibernate and Tortoise SELECT FOR UPDATE support aurora-dsql-orms#626
• Samples: Refresh Aurora DSQL SELECT FOR UPDATE sample guidance aws-samples/aurora-dsql-samples#1821

[mchenjh]

Review pass 1

Reviewed the Kiro steering rollout finalized in commit 889603e with 16+ independent roles. Findings around Rails transaction boundaries, joined-query wording, lock-clause support, SQLSTATE 40001 retries, and 10 MiB locked-primary-key accounting were addressed in the canonical guidance and mirrored here.

Validation: the Kiro steering file is byte-identical to the canonical agent-plugin guidance.

[mchenjh]

Review pass 2

A fresh 16-reviewer convergence pass was completed, followed by direct current-file verification. No unresolved behavioral or CI-blocking findings remain in commit 889603e.

Final validation: canonical and Kiro steering files are byte-identical, the agent-side deterministic suite passed 60 tests, and the MCP diff passes git diff --check. The full model eval infrastructure timed out before producing a subject response; details are recorded on the canonical agent-plugin PR.