feat(db): implement database migration system with version tracking a…

[uche102]

File Action Description
backend/src/db/migrations/003_create_schema_migrations.sql New Migration file creating schema_migrations tracking table
backend/src/db/migrations/tracker.ts New Version tracking helper module
backend/src/db/migrations/runner.ts New Core migration execution & rollback engine
backend/src/db/migrations/index.ts New Public migration API exports
backend/src/db/migrations/runner.test.ts New Unit test suite for migration lifecycle
backend/src/db/migrations/001_add_stats_indexes.sql Modify Added -- DOWN block for rollback
backend/src/db/migrations/002_create_tasks_table.sql Modify Added -- DOWN block for rollback
backend/src/config/index.ts Modify Added AUTO_MIGRATE configuration option
backend/src/index.ts Modify Runs migrations on server startup
backend/src/api/routes/health.ts Modify Implemented GET /migrations handler
backend/src/api/app.ts Modify Mounted GET /migrations route
-Closes #274

[vercel]

@uche102 is attempting to deploy a commit to the Jaja's projects Team on Vercel.

A member of the Team first needs to authorize it.

[devJaja]

nice implementation @uche102

Kindly resolve the conflicts