useFilteredTestCases should expose a filtered flag for consistent empty-state messaging #558

🤔 What's the problem you've observed?

useFilteredTestCases (added in #545) returns only ReadonlyArray<ExpandedTestCase>, but its sibling useFilteredDocuments returns { results, filtered } where filtered indicates whether any search/tag/status criteria are currently active.

Consumers that use useFilteredTestCases such as the Timeline component being built in #524 cannot distinguish between two different empty states:

"No scenarios were executed" (nothing ran)
"No scenarios match your query and/or filters" (something ran but was filtered out)

This forces consumers to either call useSearch directly (breaking the abstraction that #545 was specifically designed to provide) or show an inaccurate message to the user.

✨ Do you have a proposal for making it better?

Change useFilteredTestCases to return a consistent shape matching useFilteredDocuments:

return { results, filtered }

The hook already imports useSearch, so deriving filtered requires no new dependencies. The filtered flag can be computed the same way useFilteredDocuments computes it from whether hideStatuses, tagExpression, or a text search query is active.

This keeps the abstraction intact, makes both hooks consistent with each other and unblocks Timeline from showing accurate empty-state messaging without leaking search internals into the component.

📚 Any additional context?

No response