block-editor test suite is red on main: 16 suites / 37 tests failing after the Angular 22 migration

Description

nx run block-editor:test is red on main: 16 of 29 suites and 37 of 122 tests fail. This is fallout from the Angular 22 migration, not from any single recent change — libs/block-editor is byte-identical between main and the strict-mode branch, and the failures reproduce on both.

Found while working #35955 (TS strict mode for block-editor). Strict mode landed with the suite left exactly as it was: the same 38 failing entries by name, before and after. That work is type-only and does not touch these failures — but it also means block-editor currently has no runtime safety net, which is the real cost.

Failure causes

Every failure traces to one of four mechanical causes. None of them are logic bugs.

Affected components: TestComponent, TestFormComponent, FileUploadMockComponent, UploadPlaceholderComponent, DotImageEditorPopoverComponent, AIContentPromptComponent.

Acceptance Criteria

• nx run block-editor:test passes — 0 failing suites, 0 failing tests.
• Standalone components move from declarations to imports in every affected TestBed.configureTestingModule call.
• The TipTap editor mock covers the v3 surface the components actually call (setEditable, destroy, …), or the specs build a real Editor where that is cheaper.
• SuggestionsComponent's spec provides SuggestionsService.
• No test is deleted or skipped to reach green. If a test is genuinely obsolete, say why in the PR.

Notes

Two related repairs already landed with #35955 and are not part of this issue:

• asset-form.component.spec.ts was an orphan spec for ImageTabviewFormComponent, a component that no longer exists on main. Deleted.
• dot-upload-asset.component.spec.ts imported DotUploadFileService from block-editor's shared barrel; it lives in @dotcms/data-access. The stale import meant the spec provided a different token than the component injected.

libs/block-editor is @deprecated — kept on the rollback path behind FEATURE_FLAG_NEW_BLOCK_EDITOR until the new TipTap-v3 editor exits QA. That is precisely why the suite needs to work: it guards the fallback.

Start by running nx run block-editor:test and inspect the affected specs under libs/block-editor, focusing on each TestBed.configureTestingModule call and the shared TipTap editor mock. Update the listed standalone-component declarations, mock methods, and SuggestionsService provider without deleting or skipping tests. Done means the command reports zero failing suites and tests.