fix: migrate lint script from next lint to eslint cli

[Ishant5436]

Summary

Migrates the linting script from next lint to the eslint CLI before the next lint command is removed in Next.js 16.

Changes

• package.json: updated lint script from next lint to eslint .
• package.json: added lint:fix script (eslint . --fix) for convenience
• .eslintrc / config: confirmed compatible with direct eslint invocation

Testing

• npm run lint — passes with no warnings or errors
• npm run build — passes
• CI Lint step confirmed green locally

[Ishant5436]

just checking: noticed the issue said 'limited only to the creator', but I already had this done. Let me know if you still want to accept external PRs for this or if I should just close it!