Migration Angular 20 -> 21 : fin de la migration securite (0 vulnerabilite npm)

- ng update @angular/core@21 @angular/cli@21 (corrige GHSA-jrmj-c5cx-3cw6, XSS SVG)
- Migration automatique des templates vers le control flow natif (@if/@for, 138 fichiers)
- Correction des 5 `track` invalides generes par la migration (trackBy a 1 argument
  -> track $index) + suppression des fonctions trackBy mortes
- TypeScript 5.9, zone.js 0.15 ; npm audit : 0 vulnerabilite

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

web/src/main.ts

@@ -3,7 +3,7 @@ import { AppComponent } from './app/app.component';
 import { PreloadAllModules, provideRouter, withPreloading } from '@angular/router';
 import { routes } from './app/app.routes';
 import { provideHttpClient, withInterceptors } from '@angular/common/http';
-import { APP_INITIALIZER } from '@angular/core';
+import { APP_INITIALIZER, provideZoneChangeDetection } from '@angular/core';
 import { ConfigService } from './app/services/config.service';
 import { sessionExpiredInterceptor } from './app/interceptors/session-expired.interceptor';
 
@@ -14,7 +14,7 @@ import { sessionExpiredInterceptor } from './app/interceptors/session-expired.in
 // (acceptable pour une app interne ou toutes les routes seront visitees).
 bootstrapApplication(AppComponent, {
   providers: [
-    provideRouter(routes, withPreloading(PreloadAllModules)),
+    provideZoneChangeDetection(),provideRouter(routes, withPreloading(PreloadAllModules)),
     provideHttpClient(withInterceptors([sessionExpiredInterceptor])),
     {
       provide: APP_INITIALIZER,