Angular 21 upgrade

[cdavalos7]

Motivation for features / changes

Upgrades Angular 20 → 21 (with matching NgRx, Material, TypeScript, Node.js, and Bazel-toolchain updates), and fixes the karma test regressions that surfaced from that upgrade. Following official steps https://angular.dev/update-guide?v=20.0-21.0&l=3

Technical description of changes

1. Upgraded @angular/* core, cdk, material, forms, router, animations, localize, platform-browser(-dynamic), cli, compiler, compiler-cli, build, build-angular and @ngrx/* (store, effects) from 20 to 21 and TypeScript 5.8.3 to 5.9.3.
2. Upgrade Node.js 22.23.1 to 24.18.0 in WORKSPACE, updated the pinned GitHub Actions (checkout, setup-python, setup-node, cache, upload-artifact) in ci.yml to match and avoid CI checks errors.
3. tsconfig.json: switch moduleResolution from node to bundler, required by Angular 21, disable @bazel/tsetse lint rules that crash under TS 5.9 against concatjs's harcoded tsutils@3.21.0.
4. Patch @bazel/concatjs to map each Angular/CDK/NgRx package new folder structure: types/*.d.ts layout, so Bazel's TS rules can still resolve type declarations.
5. app_module.ts: explicitly add provideZoneChangeDetection(), no longer implicit in Angular 21.
6. column_selector_component.ts: drop the unused ['$event'] arg from three @HostListener decorators.
7. Test fixes for Angular 21 regressions:

• testing/initialize_testbed.ts, register provideZoneChangeDetection() globally for TestBed, working around a confirmed Angular 21 regression (Many NG0100 errors in Karma unit tests after updating to Angular 21 angular/angular-cli#32047)
• header_test.ts, scalar_card_test.ts, scalar_card_line_chart_test.ts: update hardcoded date-string assertions for DatePipe's new U+202F, before AM/PM for Angular 21 updated CLDR data.
• testing/material.ts, filter_input_test.ts: query document.body instead of OverlayContainer.getContainerElement() for autocomplete options since Angular Material's overlay panel now renders in a separate cdk-overlay-connected-position-bounding-box.

Screenshots of UI changes (or N/A)

Detailed steps to verify changes work correctly (as executed by you)

Alternate designs / implementations considered (or N/A)