We've committed the package-lock.json to the backend repository to prevent transitive dependency drift, which caused recent build breakages due to unexpected type definition updates. With a locked dependency tree established, we've also reverted the build process to strict tsc, ensuring type errors correctly fail the build again. This change makes our development and deployment environments consistent, eliminating the 'works on my machine' class of issues. Dependency hell finally handled

Backend: Enforcing reproducible builds by committing lockfile and tightening type safety - subh05sus/sparkmentor