fix(deps): retarget Angular upgrade to 20, not 21 (CI install was broken)

Retargets @angular/* to 20.3.26/cdk 20.2.14, reverts main.ts's
21-only bootstrap option, and widens Clarity's vendored peerDependencies
metadata to declare Angular 20 support (verified compatible; only 21 actually breaks it).

client/package.json

@@ -41,15 +41,15 @@
   },
   "private": true,
   "dependencies": {
-    "@angular/animations": "^21.2.18",
-    "@angular/cdk": "^19.2.19",
-    "@angular/common": "^21.2.18",
-    "@angular/compiler": "^21.2.18",
-    "@angular/core": "^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",
+    "@angular/animations": "^20.3.26",
+    "@angular/cdk": "^20.2.14",
+    "@angular/common": "^20.3.26",
+    "@angular/compiler": "^20.3.26",
+    "@angular/core": "^20.3.26",
+    "@angular/forms": "^20.3.26",
+    "@angular/platform-browser": "^20.3.26",
+    "@angular/platform-browser-dynamic": "^20.3.26",
+    "@angular/router": "^20.3.26",
     "@cds/core": "^6.15.1",
     "@clr/angular": "file:libraries/clr-angular-17.9.0.tgz",
     "@clr/icons": "^13.0.2",
@@ -90,14 +90,14 @@
     "zone.js": "~0.15.1"
   },
   "devDependencies": {
-    "@angular-devkit/build-angular": "^21.2.19",
+    "@angular-devkit/build-angular": "^20.3.32",
     "@angular-eslint/builder": "19.8.1",
     "@angular-eslint/eslint-plugin": "19.8.1",
     "@angular-eslint/eslint-plugin-template": "19.8.1",
     "@angular-eslint/schematics": "19.8.1",
     "@angular-eslint/template-parser": "19.8.1",
-    "@angular/cli": "^21.2.19",
-    "@angular/compiler-cli": "^21.2.18",
+    "@angular/cli": "^20.3.32",
+    "@angular/compiler-cli": "^20.3.26",
     "@babel/plugin-proposal-private-methods": "^7.18.6",
     "@compodoc/compodoc": "^2.0.0",
     "@cypress/webpack-preprocessor": "^5.17.1",
@@ -143,4 +143,4 @@
     "uuid": "11.1.1",
     "lighthouse": "13.4.0"
   }
-}
+}

client/src/main.ts

@@ -1,8 +1,5 @@
-import { provideZoneChangeDetection } from '@angular/core'
 import { platformBrowserDynamic } from '@angular/platform-browser-dynamic'
 
 import { AppModule } from './app/'
 
-platformBrowserDynamic().bootstrapModule(AppModule, {
-  applicationProviders: [provideZoneChangeDetection()]
-})
+platformBrowserDynamic().bootstrapModule(AppModule)