Implement database migration dry-run and rollback validation tooling

[Smartdevs17]

Context

Database migrations are applied directly to production with no dry-run capability. Failed migrations require manual database intervention and cause downtime.

Current Limitation/Problem

No dry-run, rollback testing, or schema drift detection. A failed ALTER TABLE migration locks the table for minutes.

Expected Outcome

Migration tooling: dry-run on read replica, automated rollback testing (down+up in CI), zero-downtime migration patterns (expand-migrate-contract), and schema drift detection.

Acceptance Criteria

• Dry-run: run migration against read replica, report warnings and row counts, no actual changes
• Rollback testing: CI runs migrate:down then migrate:up, both must succeed for every migration
• Zero-downtime helper: expand-migrate-contract pattern with automated phase transitions
• Schema drift detection: compare actual DB schema with expected schema from migrations, alert on drift
• Migration linting: detect common issues (missing down migration, destructive changes without approval flag)
• Lock detection: warn if migration requires ACCESS EXCLUSIVE lock that blocks writes
• Edge case: migration timeout (configurable, default 30s, with progress logging)

Technical Scope

• scripts/db-dry-run.sh - dry-run script against read replica
• scripts/db-rollback-test.sh - rollback CI test (down + up)
• scripts/db-validate.sh - migration linter and schema drift checker
• db/migrations/ - migration template with zero-downtime phases
• .github/workflows/db-migration.yml - CI migration validation workflow
• backend/shared/db/ - migration runner with advisory lock support

[susanyusuf]

@susanyusuf has applied to work on this issue as part of the Stellar Wave Program's 6th wave.

Hi Maintainer,I'd like to take on this issue. I can build the automated database migration tooling to ensure safe, zero-downtime schema updates and prevent production locking.Create scripts/db-dry-run.sh to safely simulate migrations against a read replica and report row count impacts and warnings.
Build scripts/db-rollback-test.sh to enforce automated down + up validation within the CI pipeline.

ℹ️ Repo Maintainers: To accept this application, review their application or assign @susanyusuf to this issue.

[drips-wave]

Congratulations, @susanyusuf! 🎉 Your application was accepted by the repo's maintainers, and the issue is due on June 30, 2026.

🧑‍💻 @susanyusuf: Please resolve the issue such that the repo's maintainers have enough time to review your contribution before the due date. You'll earn Points for completing the issue on-time, which will make you eligible for a share of the Stellar Wave Program's reward pool.

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🌊 Happy Wave 🌊

[drips-wave]

This issue has been completed by @susanyusuf as part of the Stellar Wave Program's 6th Wave 🥳

😎 @susanyusuf: You earned 200 Points for completing this issue! After the current Wave ends, you'll be eligible for a percentage of the Wave's reward pool based on the percentage of total points you've earned. Learn more here. You can also Leave a review to share your experience working on this issue.

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