Fix the pre-existing eslint errors and enable lint in CI - #54

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/setup-node@v4, pnpm/action-setup@v4. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/

'Bmax' is defined but never used

React Hook useMemo has missing dependencies: 'x' and 'y'. Either include them or remove the dependency array

React Hook useMemo has missing dependencies: 'x' and 'y'. Either include them or remove the dependency array

React Hook useEffect has a missing dependency: 'opStatuses'. Either include it or remove the dependency array

React Hook useCallback has a missing dependency: 'demoSteps.length'. Either include it or remove the dependency array

'_id' is defined but never used

React Hook useEffect has a missing dependency: 'total'. Either include it or remove the dependency array

React Hook useEffect has a missing dependency: 'total'. Either include it or remove the dependency array

'gridH' is assigned a value but never used

'gridW' is assigned a value but never used