feat: upgrade Node.js from 8.15.1+ to 18.20.8 LTS

[devin-ai-integration]

feat: upgrade Node.js from 8.15.1+ to 18.20.8 LTS

Summary

This PR upgrades the bank-client application from Node.js 8.15.1+ to Node.js 18.20.8 LTS, representing a major version jump across 10 Node.js releases. The upgrade includes:

Core Version Updates:

• Updated package.json engines field to require node: ">=18.0.0"
• Updated .nvmrc to specify Node.js 18.20.8
• Updated README.md system requirements to Node.js v18.20+

Critical Compatibility Changes:

• Replaced offline-plugin with workbox-webpack-plugin due to Node.js 18 incompatibility
• Updated service worker registration from offline-plugin runtime to modern navigator.serviceWorker.register()
• Added NODE_OPTIONS=--openssl-legacy-provider to build and start scripts for Webpack 4 + Node.js 18 compatibility

The build process and development server have been verified to work with Node.js 18, but this represents a significant architectural change that requires thorough testing.

Review & Testing Checklist for Human

🔴 CRITICAL - Complete Application Testing Required

• Test complete application functionality in browser - Load the app, navigate through all major user flows (login, dashboard, transactions, etc.) to ensure no runtime errors or broken functionality
• Verify service worker/offline functionality - Test that the app works offline, caches resources correctly, and service worker registration completes without errors in browser dev tools
• Test build reproducibility - Run rm -rf node_modules yarn.lock && yarn install && yarn build in a clean environment to ensure consistent builds
• Verify development experience - Test that yarn start works correctly with hot reloading, error overlays, and all development features
• Check for runtime errors - Monitor browser console for any new errors, warnings, or performance issues that weren't present before

Recommended Test Plan:

1. Clean install: rm -rf node_modules && yarn install
2. Build verification: yarn build (should complete without errors)
3. Development server: yarn start (should start and be accessible)
4. Browser testing: Open app in browser, test all major user flows
5. Service worker: Check Application tab in dev tools for service worker registration
6. Offline testing: Disconnect network and verify app still functions

---

Diagram

%%{ init : { "theme" : "default" }}%%
graph TD
    subgraph "Core Configuration"
        A["package.json<br/>engines.node: 8.15.1+ → 18.0.0+<br/>+ NODE_OPTIONS flags"]:::major-edit
        B[".nvmrc<br/>lts/dubnium → 18.20.8"]:::major-edit
        C["README.md<br/>v12.18+ → v18.20+"]:::minor-edit
    end
    
    subgraph "Service Worker Architecture"
        D["webpack.prod.babel.js<br/>OfflinePlugin → GenerateSW"]:::major-edit
        E["app/app.js<br/>offline-plugin/runtime → navigator.serviceWorker"]:::major-edit
        F["yarn.lock<br/>+ workbox-webpack-plugin<br/>- offline-plugin"]:::major-edit
    end
    
    subgraph "Build Process"
        G["Build Scripts<br/>NODE_OPTIONS=--openssl-legacy-provider"]:::context
        H["Development Server<br/>Hot reload + error handling"]:::context
    end
    
    A --> D
    A --> G
    D --> E
    F --> D
    G --> H
    
    subgraph Legend
        L1["Major Edit"]:::major-edit
        L2["Minor Edit"]:::minor-edit
        L3["Context/No Edit"]:::context
    end
    
    classDef major-edit fill:#90EE90
    classDef minor-edit fill:#87CEEB
    classDef context fill:#FFFFFF

Loading

Notes

⚠️ High-Risk Changes:

• This is a 10 major version jump in Node.js (8 → 18), which could introduce subtle breaking changes
• Service worker implementation completely replaced - offline functionality needs thorough validation
• Using OpenSSL legacy provider workaround indicates deeper Webpack 4 + Node.js 18 compatibility issues

Technical Context:

• The NODE_OPTIONS=--openssl-legacy-provider flag is required because Webpack 4 uses deprecated OpenSSL functions that were removed in Node.js 17+
• Workbox is the modern, Google-maintained replacement for the unmaintained offline-plugin
• All 2020-era dependencies (React 16, Webpack 4, Babel 7) should be compatible with Node.js 18, but edge cases may exist

Session Info:

• Link to Devin run: https://app.devin.ai/sessions/0be99ddb66824ddda66187811709728e
• Requested by: @akkp-windsurf

[devin-ai-integration]

🤖 Devin AI Engineer

I'll be helping with this pull request! Here's what you should know:

✅ I will automatically:

• Address comments on this PR. Add '(aside)' to your comment to have me ignore it.
• Look at CI failures and help fix them

Note: I can only respond to comments from users who have write access to this repository.

⚙️ Control Options:

• Disable automatic comment and CI monitoring