chore: upgrade Angular 20 to 21

Ran ng update @angular/core@21 @angular/cli@21. Updated tsconfig lib to
es2022. Build and all 84 tests pass.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: cyongverto

package.json

@@ -20,23 +20,23 @@
     "caniuse-lite": "^1.0.30001806"
   },
   "dependencies": {
-    "@angular/animations": "^20.3.25",
-    "@angular/common": "^20.3.25",
-    "@angular/compiler": "^20.3.25",
-    "@angular/core": "^20.3.25",
-    "@angular/elements": "20.3.25",
-    "@angular/forms": "^20.3.25",
-    "@angular/platform-browser": "^20.3.25",
-    "@angular/platform-browser-dynamic": "^20.3.25",
-    "@angular/router": "^20.3.25",
+    "@angular/animations": "^21.2.18",
+    "@angular/common": "^21.2.18",
+    "@angular/compiler": "^21.2.18",
+    "@angular/core": "^21.2.18",
+    "@angular/elements": "21.2.18",
+    "@angular/forms": "^21.2.18",
+    "@angular/platform-browser": "^21.2.18",
+    "@angular/platform-browser-dynamic": "^21.2.18",
+    "@angular/router": "^21.2.18",
     "rxjs": "~7.5.0",
     "tslib": "^2.3.0",
     "zone.js": "~0.16.2"
   },
   "devDependencies": {
-    "@angular-devkit/build-angular": "^20.3.32",
-    "@angular/cli": "~20.3.32",
-    "@angular/compiler-cli": "^20.3.25",
+    "@angular-devkit/build-angular": "^21.2.19",
+    "@angular/cli": "~21.2.19",
+    "@angular/compiler-cli": "^21.2.18",
     "@babel/helper-remap-async-to-generator": "^7.29.7",
     "@types/jasmine": "~4.0.0",
     "@types/node": "22",
@@ -51,7 +51,7 @@
     "karma-jasmine": "~5.1.0",
     "karma-jasmine-html-reporter": "~2.2.0",
     "lite-server": "^2.6.1",
-    "ng-packagr": "20.3.2",
+    "ng-packagr": "21.2.5",
     "npm-run-all": "^4.1.5",
     "prettier": "^3.9.5",
     "primeicons": "^6.0.1",

tsconfig.json

@@ -26,7 +26,6 @@
     "target": "ES2022",
     "module": "es2020",
     "allowSyntheticDefaultImports": true,
-    "lib": ["es2020", "dom", "dom.iterable"],
     // Required: Angular's inject() field initializers depend on decorator-based class field semantics; removing this would silently break DI at runtime.
     "useDefineForClassFields": false
   },