Search roles by title

Candidates need a fast way to narrow the open roles list when Caldova has many postings. Add a search box that filters role cards by title without requiring a page reload.

Acceptance criteria

• The home page includes a labeled search input that filters roles by title case-insensitively.
• Clearing the search restores the full roles list.
• A helpful empty state appears when no roles match.
• Search controls and results are accessible and include stable data-testid attributes.
• Unit tests cover the filtering helper.
• Playwright tests cover searching and the empty state.

Start at the home page and inspect how the roles list and role cards are rendered. Add the labeled title search, accessible controls, stable data-testid attributes, and empty state described in the acceptance criteria. Verify the filtering helper with unit tests, then run Playwright coverage for searching, clearing the query, and no matches.