Up/Down arrow keys now move focus through the recents list in the
welcome dialog; Home/End jump to the first/last entry. Tab / Enter
/ Space behaviour is untouched — arrows are additive. Covered by
two UI tests (arrow roundtrip + Home/End) that poll for the async
IDB load instead of a fixed delay.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>