[Rodrigoue9]

Summary

• Implements release readiness verification gates for database and schema migrations (core/migration/release-readiness.ts).
• Normal path: Verifies that pending migrations have declarative schema versions, dry-run preview evidence, documented rollback/forward-fix procedures, and registered post-migration invariant checks.
• Rollback evidence: Generates tamper-evident, cryptographically verifiable rollback evidence bundles (RollbackEvidenceBundle) with SHA-256 digests of pre-migration snapshots and rollback procedures.
• Authorization path: Enforces role-based access control, requiring maintainer or release_manager roles and rejecting unauthorized callers with detailed audit trails.
• Retry path: Resilient readiness probe evaluation with configurable exponential backoff to handle transient cluster and storage health checks.
• Executable verification: Ships scripts/verify-migration-readiness.mjs and npm script npm run verify:migration-readiness.
• Automated test suite: Covers normal, failure, retry, authorization, and rollback evidence integrity paths in core/migration/__tests__/releaseReadiness.test.ts.

Closes #322

Test plan

• node scripts/verify-migration-readiness.mjs passes with verified evidence bundles
• node scripts/release-readiness-gate.mjs passes (4/4 gates satisfied)

[BigDella]

Merged after updating/checking against the live base branch and passing the required Malware guard. The earlier status comment was based on an older GitHub merge preview or a branch that did not need updating; it was not a finding that this contribution introduced malware.