chore(deps): upgrade Angular 20 → 21

Migrates to Angular 21.0.0: updates tsconfig lib to es2022, migrates
bootstrap options in main.ts, and completes control flow migration
(*ngFor/*ngIf → @for/@if) in jumps and jumps-by-month templates to
resolve duplicate ng-template name conflicts skipped by the schematic.
Also fixes pre-commit hook to load nvm before running tests.

.husky/pre-commit

@@ -1,2 +1,5 @@
+export NVM_DIR="$HOME/.nvm"
+[ -s "$NVM_DIR/nvm.sh" ] && \. "$NVM_DIR/nvm.sh"
+nvm use 20.19.6
 npm test -- --watch=false
-npx lint-staged
+npx lint-staged