Add behavior-focused spec files for untested dashboard/hub components

[Ma77Ball]

Task Summary

Several dashboard and hub components ship without unit tests. Add a
behavior-focused .spec.ts file alongside each component listed below.
Target observable behavior — event handlers, service calls, navigation,
form submission — and avoid asserting on implementation details like URL
string literals.

Components needing specs:

• dashboard/component/user/share-access/share-access.component.ts
  (form validation, email sending, access-grant flow)
• hub/component/hub.component.ts
  (navigation and route subscription logic)
• hub/component/landing-page/landing-page.component.ts
• hub/component/about/local-login/local-login.component.ts
• hub/component/workflow/detail/hub-workflow-detail.component.ts
• dashboard/component/user/search-bar/search-bar.component.ts
  (search behavior, debouncing)
• dashboard/component/user/user-dataset/user-dataset.component.ts
  (list rendering, deletion, pagination)
• dashboard/component/user/user-dataset/user-dataset-list-item/
  user-dataset-list-item.component.ts

Conventions: place each spec next to its component, mock injected services
with Jasmine spies, use fakeAsync/tick for async behavior, and assert on
spy calls / emitted outputs rather than URL strings.

Task Type

• Refactor / Cleanup
• DevOps / Deployment / CI
• Testing / QA
• Documentation
• Performance
• Other

[Ma77Ball]

/take