chore(project): Implement and Enforce Linting and Formatting

[Taleef7]

As a development team, we need an automated way to enforce a consistent code style across the entire project. This prevents style debates, improves readability, and helps catch potential bugs early.

Acceptance Criteria:

• ESLint and Prettier are configured for both the backend (Node.js) and frontend (React) codebases.
• npm scripts (lint, format) are added to the package.json of each service and the root.
• A pre-commit hook (using husky and lint-staged) is set up to automatically format and lint staged files before they are committed.
• The CI pipeline (from Issue 3.3) includes a step to run the linter, failing the build if there are any linting errors.