Date row now shows All time | 7d | 30d | 6mo | 2026 | 2025 | ... derived
from actual activity data. Year pills use a bounded [Jan 1, Jan 1+1) range
via a new dateTo field on ActivityFilter; rolling-window presets keep an
open upper bound.
Adds a fourth tab visible only on Android API 29+ (full phone, not Karoo).
Filters by sport pill, date preset (7d/30d/6mo/year), and sort order
(newest/distance/elevation). Paginated FlatList with the same activity cards.
ActivityCard extracted to mobile/components/ActivityCard.tsx so both the
feed tab and the new search tab share the same component without duplication.