analysis.feature and full-ui-path.feature still used exact-match
[data-e2e=toggle-btn] which broke after #178 changed the attribute to
compound values. Switch to [data-e2e~=configure-btn].
Add dedicated data-e2e selectors (configure-btn, verify-btn, prepare-btn)
to StudioPage toggle buttons and update E2E tests to use waitFor + click
on these selectors instead of locateAll index tricks. Fixes timeout in
rechunk.feature caused by race with async feature flag loading.
Closes#176