build: use @angular/build builders

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

angular.json

@@ -15,7 +15,7 @@
       "prefix": "app",
       "architect": {
         "build": {
-          "builder": "@angular-devkit/build-angular:application",
+          "builder": "@angular/build:application",
           "options": {
             "outputPath": {
               "base": "dist",
@@ -108,7 +108,7 @@
           "defaultConfiguration": "production"
         },
         "serve": {
-          "builder": "@angular-devkit/build-angular:dev-server",
+          "builder": "@angular/build:dev-server",
           "options": {
             "port": 4200
           },
@@ -123,10 +123,10 @@
           "defaultConfiguration": "development"
         },
         "extract-i18n": {
-          "builder": "@angular-devkit/build-angular:extract-i18n"
+          "builder": "@angular/build:extract-i18n"
         },
         "test": {
-          "builder": "@angular-devkit/build-angular:karma",
+          "builder": "@angular/build:karma",
           "options": {
             "watch": false,
             "browsers": "ChromeHeadless",