Fix SonarQube test assertion specificity

[igorsatsyuk]

What changed

• replaced generic length-based expectations in frontend specs with more specific assertions over rendered ids and grouped keys
• tightened the dashboard paging assertion to verify the exact ids returned to the view instead of only checking array length
• kept the behavior of the tests the same while addressing SonarQube maintainability feedback

Why

SonarQube flagged several generic assertions in the Angular spec suite. These checks were valid but not very descriptive, so the tests now assert the expected structure and content more directly.

Impact

• no production code changes
• clearer and more intention-revealing frontend tests
• SonarQube warnings for these assertions should be resolved

Validation

• npm test -- --watch=false --browsers=ChromeHeadless