feat!: migrate to Ionic 9 and support Angular 21-22

[rdlabo]

Summary

This is a breaking platform migration released as the new 22.x package line for the published libraries and their consumers.

• require Ionic Angular 9 for kit and photo-editor
• support Angular 21 and 22 across all published package peer dependencies
• require Capacitor 7+ for native consumers, matching the Ionic 9 runtime requirement
• migrate Ionic standalone imports from @ionic/angular/standalone to @ionic/angular and move AngularDelegate to @ionic/angular/common
• upgrade the development workspace to Angular 22.1, TypeScript 6, Ionic Toolkit 13, Angular ESLint 22, and ng-packagr 22
• constrain Node.js to the versions officially supported by Angular 22
• add an Angular 21 / TypeScript 5.9 compatibility build to CI
• remove unused @angular/fire, whose peer range does not support Angular 22
• add docs/migration.md and update the README compatibility matrix

Breaking changes

Consumers should run npx @ionic/migrate, the Ionic-recommended migration path for applications, and review its changes together with the manual audit in this repository. The migrator does not support Angular library workspaces, so this library was migrated manually.

Consumers must upgrade to the 22.x package line and Ionic 9. Native applications must also use Capacitor 7 or 8. Applications importing standalone Ionic APIs from @ionic/angular/standalone must switch to @ionic/angular; applications intentionally using lazy wrappers must use @ionic/angular/lazy. Angular 21/22 change-detection behavior and Ionic 9 component changes should be audited as described in the migration guide.

See docs/migration.md and the upstream Ionic 9 breaking changes.

Validation

• npm run lint
• npm run prebuild
• npm run build with Angular 22 / TypeScript 6
• npm run build with Angular 21 / TypeScript 5.9
• npx ng test kit --watch=false (49 files, 937 tests)
• all project tests and e2e in GitHub Actions
• Prettier and git diff --check