Stringhtened migration drift checks across environmtents

[aboyejirebecca-prog]

Summary

• Add --env <label> flag to check-migration-drift.js so every check output (console and JSON) is tagged with its environment (local, ci-remote, etc.), making cross-environment comparison unambiguous
• Fix broken PR comment in migration-drift-check.yml — was reading process.env.STATUS (never set), so always showed "❌ Drift detected!" regardless of result; now captures --json output and renders actual issue list ([duplicate], [conflict], [unapplied_migration], [orphaned_migration]) into the comment body
• Add verify-local-database CI job to migration-drift-check.yml — spins up a local Supabase stack on every PR, applies all migrations, runs --verify-db --env local, and posts a dedicated PR comment with applied/filesystem counts and any issues found
• Add drift check step to database.yml — after migrations are applied to the local stack, runs --verify-db --env local --json and fails the job with per-issue output if state diverges from filesystem
• Add Environment-Aware Output and Conflicting Migration History Detection test suites covering env field in JSON output, local vs ci-remote label distinction, cross-environment count divergence, and orphaned issue timestamps
• Expand MIGRATION_REMEDIATION.md Case 6 (Cross-Environment Divergence) with CI job references and new --env commands; add Case 7 for CI-remote-only orphaned migrations

Test plan

• Run node scripts/check-migration-drift.js --json — verify "env": "unknown" appears in output
• Run node scripts/check-migration-drift.js --env local --json — verify "env": "local" in output
• Run npm run test:migrations — all existing tests pass, new Environment-Aware Output and Conflicting Migration History Detection suites pass
• Open a PR that touches supabase/migrations/ — confirm three PR comments appear: 🔍 Migration Drift Check, 🖥️ Local Database Drift Check, 📊 CI Remote Database Drift Check
• Confirm 🔍 Migration Drift Check comment lists actual [duplicate] / [conflict] items when drift exists, not just pass/fail
• Confirm database.yml workflow fails with ❌ Local database drift detected: [unapplied_migration] ... when a migration file is present but not applied

Closes

Fixes #657
Backlog: #63

[drips-wave]

@aboyejirebecca-prog Great news! 🎉 Based on an automated assessment of this PR, the linked Wave issue(s) no longer count against your application limits.

You can now already apply to more issues while waiting for a review of this PR. Keep up the great work! 🚀

Learn more about application limits

[aboyejirebecca-prog]

Ready for review! All tests pass. Happy to make changes if needed.