Upgrade Angular 7 → 21, Nebular 3 → 17, modernize SSR

[Copilot]

Project was on Angular 7 (2018) with a deprecated @nguniversal SSR setup and a one-line README.

Dependencies

• All @angular/*: 7 → 21.2.17; @nebular/theme: 3 → 17; TypeScript: 3.1 → 5.9; RxJS: 6 → 7.8; zone.js: 0.8 → 0.16
• Added @angular/ssr + express 5; pinned @angular/cdk to ~21.0.0 (Nebular 17 uses internal CDK symbols removed in 21.2.x)
• Removed: @nguniversal/*, @angular/http, domino, core-js, tslint, phantomjs, protractor, webpack-cli, ts-loader

SSR

Replaced @nguniversal/express-engine + webpack bundle + domino window polyfills with the Angular-native CommonEngine:

// server.ts — before: custom NgFactory + domino global patching
// server.ts — after:
import { CommonEngine } from '@angular/ssr/node';
const commonEngine = new CommonEngine();
server.get('**', (req, res, next) => {
  commonEngine.render({ bootstrap: AppServerModule, ... })
    .then(html => res.send(html))
    .catch(next);
});

angular.json now uses the unified application builder (browser + server in one pass); webpack.server.config.js deleted.

Angular 21 Breaking Changes

• standalone: false added to all @Component decorators (Angular 19+ defaults to standalone)
• BrowserModule.withServerTransition() removed (dropped in v21) → plain BrowserModule
• Lazy loading updated from deprecated string syntax ('./sample/sample.module#SomePageModule') to dynamic import()
• class Hero → interface Hero; strict-mode property initialization fixed across components
• main.server.ts exports AppServerModule as default (required by Angular 17+ SSR bootstrap)

Config

• tsconfig.json: ES2022 target/module, moduleResolution: bundler, strict mode
• Root-level tsconfig.app.json / tsconfig.spec.json added (required by new builder)
• karma.conf.js: karma-coverage replaces deprecated karma-coverage-istanbul-reporter

README

Rewritten with setup steps, project structure, SSR architecture explanation, scripts reference, and dependency table.