feat(mobile): search/filter tab — sport, date, sort; hidden on Karoo

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.

mobile/app/(tabs)/_layout.tsx

@@ -1,6 +1,9 @@
 import { Tabs } from 'expo-router';
+import { Platform } from 'react-native';
 import { useTheme } from '@/ThemeContext';
 
+const isKaroo = Platform.OS === 'android' && (Platform.Version as number) < 29;
+
 export default function TabLayout() {
   const theme = useTheme();
   return (
@@ -20,6 +23,14 @@ export default function TabLayout() {
         name="import"
         options={{ title: 'Import', tabBarIcon: ({ color }) => <TabIcon label="↑" color={color} /> }}
       />
+      <Tabs.Screen
+        name="search"
+        options={{
+          title: 'Search',
+          tabBarIcon: ({ color }) => <TabIcon label="⌕" color={color} />,
+          href: isKaroo ? null : '/search',
+        }}
+      />
       <Tabs.Screen
         name="settings"
         options={{ title: 'Settings', tabBarIcon: ({ color }) => <TabIcon label="⚙" color={color} /> }}

mobile/app/(tabs)/index.tsx

@@ -1,12 +1,12 @@
 import * as FileSystem from 'expo-file-system';
 import { useFocusEffect } from 'expo-router';
 import { useSQLiteContext } from 'expo-sqlite';
-import { useRouter } from 'expo-router';
 import { useCallback, useState } from 'react';
 import { Alert, FlatList, Pressable, RefreshControl, StyleSheet, Text, TextInput, View } from 'react-native';
-import { deleteActivities, useActivities, useActivityCount, PAGE_SIZE, type ActivitySummary } from '@/db/queries';
+import { deleteActivities, useActivities, useActivityCount, PAGE_SIZE } from '@/db/queries';
 import { downloadFeed, uploadFeed } from '@/db/sync';
 import { useTheme } from '@/ThemeContext';
+import { ActivityCard } from '@/components/ActivityCard';
 
 export default function FeedScreen() {
   const db = useSQLiteContext();
@@ -255,80 +255,6 @@ function ActionButton({
   );
 }
 
-function ActivityCard({
-  activity,
-  selecting,
-  checked,
-  onToggleSelect,
-  onLongPress,
-}: {
-  activity: ActivitySummary;
-  selecting: boolean;
-  checked: boolean;
-  onToggleSelect: () => void;
-  onLongPress: () => void;
-}) {
-  const router = useRouter();
-  const theme = useTheme();
-  const km   = activity.distance_m != null ? (activity.distance_m / 1000).toFixed(1) : null;
-  const elev = activity.elevation_gain_m != null ? Math.round(activity.elevation_gain_m) : null;
-  const date = new Date(activity.started_at).toLocaleDateString(undefined, {
-    day: 'numeric', month: 'short', year: 'numeric',
-  });
-
-  function handlePress() {
-    if (selecting) onToggleSelect();
-    else router.push(`/activity/${activity.id}`);
-  }
-
-  return (
-    <Pressable
-      style={[styles.card, checked && { borderColor: theme.accent }]}
-      onPress={handlePress}
-      onLongPress={onLongPress}
-    >
-      <View style={styles.cardTop}>
-        <View style={styles.cardLeft}>
-          {selecting && (
-            <View style={[styles.checkbox, checked && { backgroundColor: theme.accent, borderColor: theme.accent }]}>
-              {checked && <Text style={styles.checkmark}>✓</Text>}
-            </View>
-          )}
-          <Text style={styles.sportIcon}>{sportIcon(activity.sport)}</Text>
-        </View>
-        <View style={styles.cardMeta}>
-          <Text style={styles.cardDate}>{date}</Text>
-          {activity.origin === 'remote'
-            ? <Text style={[styles.remoteBadge, { color: theme.accent, borderColor: theme.accent }]}>cloud</Text>
-            : !activity.synced_at && <Text style={styles.localBadge}>local</Text>
-          }
-        </View>
-      </View>
-      <Text style={styles.cardTitle} numberOfLines={1}>{activity.title}</Text>
-      <View style={styles.cardStats}>
-        {km   && <Stat label="km" value={km} />}
-        {elev != null && <Stat label="m↑" value={String(elev)} />}
-      </View>
-    </Pressable>
-  );
-}
-
-function Stat({ label, value }: { label: string; value: string }) {
-  return (
-    <View style={styles.stat}>
-      <Text style={styles.statValue}>{value}</Text>
-      <Text style={styles.statLabel}>{label}</Text>
-    </View>
-  );
-}
-
-function sportIcon(sport: string): string {
-  const icons: Record<string, string> = {
-    cycling: '🚴', running: '🏃', hiking: '🥾', swimming: '🏊', walking: '🚶',
-  };
-  return icons[sport] ?? '🏅';
-}
-
 const styles = StyleSheet.create({
   container: { flex: 1, backgroundColor: '#09090b' },
   headerRow: {
@@ -357,33 +283,6 @@ const styles = StyleSheet.create({
     color: '#f4f4f5', fontSize: 14,
   },
   list:  { padding: 16, gap: 12, paddingBottom: 80 },
-  card: {
-    backgroundColor: '#18181b', borderRadius: 12,
-    padding: 16, borderWidth: 1, borderColor: '#27272a',
-  },
-  cardTop:  { flexDirection: 'row', justifyContent: 'space-between', marginBottom: 6 },
-  cardLeft: { flexDirection: 'row', alignItems: 'center', gap: 10 },
-  sportIcon: { fontSize: 20 },
-  cardMeta: { flexDirection: 'row', alignItems: 'center', gap: 8 },
-  cardDate: { color: '#71717a', fontSize: 12 },
-  remoteBadge: {
-    fontSize: 10, borderWidth: 1,
-    borderRadius: 4, paddingHorizontal: 4,
-  },
-  localBadge: {
-    color: '#a1a1aa', fontSize: 10, borderWidth: 1,
-    borderColor: '#3f3f46', borderRadius: 4, paddingHorizontal: 4,
-  },
-  cardTitle:  { color: '#f4f4f5', fontSize: 15, fontWeight: '600', marginBottom: 10 },
-  cardStats:  { flexDirection: 'row', gap: 16 },
-  stat:       { flexDirection: 'row', alignItems: 'baseline', gap: 3 },
-  statValue:  { color: '#f4f4f5', fontSize: 16, fontWeight: '600' },
-  statLabel:  { color: '#71717a', fontSize: 12 },
-  checkbox: {
-    width: 20, height: 20, borderRadius: 4, borderWidth: 1.5,
-    borderColor: '#52525b', alignItems: 'center', justifyContent: 'center',
-  },
-  checkmark: { color: '#fff', fontSize: 12, fontWeight: '700' },
   empty: {
     flex: 1, alignItems: 'center', justifyContent: 'center', padding: 32,
   },

mobile/app/(tabs)/search.tsx

@@ -0,0 +1,145 @@
+import { useState } from 'react';
+import { FlatList, Pressable, ScrollView, StyleSheet, Text, View } from 'react-native';
+import { PAGE_SIZE, useFilteredActivities, useFilteredCount, type ActivityFilter } from '@/db/queries';
+import { ActivityCard } from '@/components/ActivityCard';
+import { useTheme } from '@/ThemeContext';
+
+type DatePreset = 'all' | '7d' | '30d' | '6mo' | 'year';
+type SortKey = 'date' | 'distance' | 'elevation';
+
+const SPORTS = [
+  { value: '',         label: 'All' },
+  { value: 'cycling',  label: '🚴 Cycling' },
+  { value: 'running',  label: '🏃 Running' },
+  { value: 'hiking',   label: '🥾 Hiking' },
+  { value: 'swimming', label: '🏊 Swimming' },
+  { value: 'walking',  label: '🚶 Walking' },
+];
+
+const DATE_PRESETS: { value: DatePreset; label: string }[] = [
+  { value: 'all',  label: 'All time' },
+  { value: '7d',   label: '7 days' },
+  { value: '30d',  label: '30 days' },
+  { value: '6mo',  label: '6 months' },
+  { value: 'year', label: 'This year' },
+];
+
+const SORTS: { value: SortKey; label: string }[] = [
+  { value: 'date',      label: 'Newest' },
+  { value: 'distance',  label: 'Distance' },
+  { value: 'elevation', label: 'Elevation' },
+];
+
+function computeDateFrom(preset: DatePreset): string {
+  if (preset === 'all') return '';
+  const pad = (n: number) => String(n).padStart(2, '0');
+  const now = new Date();
+  let d: Date;
+  if      (preset === '7d')  d = new Date(now.getTime() - 7  * 86_400_000);
+  else if (preset === '30d') d = new Date(now.getTime() - 30 * 86_400_000);
+  else if (preset === '6mo') { d = new Date(now); d.setMonth(d.getMonth() - 6); }
+  else                       d = new Date(now.getFullYear(), 0, 1);
+  return `${d.getFullYear()}-${pad(d.getMonth() + 1)}-${pad(d.getDate())}T000000Z`;
+}
+
+export default function SearchScreen() {
+  const theme = useTheme();
+  const [sport,   setSport]   = useState('');
+  const [datePre, setDatePre] = useState<DatePreset>('all');
+  const [sort,    setSort]    = useState<SortKey>('date');
+  const [limit,   setLimit]   = useState(PAGE_SIZE);
+
+  const filter: ActivityFilter = { sport, dateFrom: computeDateFrom(datePre), sort };
+  const activities = useFilteredActivities(filter, limit);
+  const total      = useFilteredCount(filter);
+  const hasMore    = activities.length < total;
+
+  return (
+    <View style={styles.container}>
+      <View style={styles.headerRow}>
+        <Text style={styles.header}>Filter</Text>
+        {total > 0 && <Text style={styles.count}>{total} activities</Text>}
+      </View>
+
+      <ScrollView horizontal showsHorizontalScrollIndicator={false}
+        style={styles.pillScroll} contentContainerStyle={styles.pillRow}>
+        {SPORTS.map(s => (
+          <Pill key={s.value} label={s.label} active={sport === s.value} accent={theme.accent}
+            onPress={() => { setSport(s.value); setLimit(PAGE_SIZE); }} />
+        ))}
+      </ScrollView>
+
+      <ScrollView horizontal showsHorizontalScrollIndicator={false}
+        style={styles.pillScroll} contentContainerStyle={styles.pillRow}>
+        {DATE_PRESETS.map(d => (
+          <Pill key={d.value} label={d.label} active={datePre === d.value} accent={theme.accent}
+            onPress={() => { setDatePre(d.value); setLimit(PAGE_SIZE); }} />
+        ))}
+      </ScrollView>
+
+      <View style={styles.sortRow}>
+        {SORTS.map(s => (
+          <Pressable key={s.value}
+            style={[styles.sortBtn, sort === s.value && { borderBottomColor: theme.accent, borderBottomWidth: 2 }]}
+            onPress={() => { setSort(s.value); setLimit(PAGE_SIZE); }}>
+            <Text style={[styles.sortText, sort === s.value && { color: theme.accent }]}>{s.label}</Text>
+          </Pressable>
+        ))}
+      </View>
+
+      {activities.length === 0 ? (
+        <View style={styles.empty}>
+          <Text style={styles.emptyText}>No activities match</Text>
+        </View>
+      ) : (
+        <FlatList
+          data={activities}
+          keyExtractor={a => a.id}
+          renderItem={({ item }) => (
+            <ActivityCard activity={item} selecting={false} checked={false}
+              onToggleSelect={() => {}} onLongPress={() => {}} />
+          )}
+          contentContainerStyle={styles.list}
+          onEndReached={() => { if (hasMore) setLimit(l => l + PAGE_SIZE); }}
+          onEndReachedThreshold={0.3}
+        />
+      )}
+    </View>
+  );
+}
+
+function Pill({ label, active, accent, onPress }: {
+  label: string; active: boolean; accent: string; onPress: () => void;
+}) {
+  return (
+    <Pressable
+      style={[styles.pill, active && { backgroundColor: accent + '33', borderColor: accent }]}
+      onPress={onPress}
+    >
+      <Text style={[styles.pillText, active && { color: accent }]}>{label}</Text>
+    </Pressable>
+  );
+}
+
+const styles = StyleSheet.create({
+  container:  { flex: 1, backgroundColor: '#09090b' },
+  headerRow: {
+    flexDirection: 'row', alignItems: 'center', justifyContent: 'space-between',
+    paddingHorizontal: 16, paddingTop: 60, paddingBottom: 12,
+  },
+  header:     { color: '#fff', fontSize: 22, fontWeight: '700' },
+  count:      { color: '#71717a', fontSize: 13 },
+  pillScroll: { flexGrow: 0 },
+  pillRow:    { flexDirection: 'row', gap: 8, paddingHorizontal: 16, paddingBottom: 10 },
+  pill: {
+    borderRadius: 20, borderWidth: 1, borderColor: '#3f3f46',
+    paddingHorizontal: 14, paddingVertical: 7,
+  },
+  pillText:   { color: '#a1a1aa', fontSize: 13, fontWeight: '500' },
+  sortRow:    { flexDirection: 'row', paddingHorizontal: 16, marginBottom: 4 },
+  sortBtn:    { marginRight: 24, paddingBottom: 8, borderBottomWidth: 2, borderBottomColor: 'transparent' },
+  sortText:   { color: '#71717a', fontSize: 13, fontWeight: '600' },
+  list:       { padding: 16, gap: 12, paddingBottom: 80 },
+  empty:      { flex: 1, alignItems: 'center', justifyContent: 'center' },
+  emptyText:  { color: '#52525b', fontSize: 15 },
+});

mobile/components/ActivityCard.tsx

@@ -0,0 +1,108 @@
+import { useRouter } from 'expo-router';
+import { Pressable, StyleSheet, Text, View } from 'react-native';
+import type { ActivitySummary } from '@/db/queries';
+import { useTheme } from '@/ThemeContext';
+
+export function ActivityCard({
+  activity,
+  selecting,
+  checked,
+  onToggleSelect,
+  onLongPress,
+}: {
+  activity: ActivitySummary;
+  selecting: boolean;
+  checked: boolean;
+  onToggleSelect: () => void;
+  onLongPress: () => void;
+}) {
+  const router = useRouter();
+  const theme = useTheme();
+  const km   = activity.distance_m != null ? (activity.distance_m / 1000).toFixed(1) : null;
+  const elev = activity.elevation_gain_m != null ? Math.round(activity.elevation_gain_m) : null;
+  const date = new Date(activity.started_at).toLocaleDateString(undefined, {
+    day: 'numeric', month: 'short', year: 'numeric',
+  });
+
+  function handlePress() {
+    if (selecting) onToggleSelect();
+    else router.push(`/activity/${activity.id}`);
+  }
+
+  return (
+    <Pressable
+      style={[styles.card, checked && { borderColor: theme.accent }]}
+      onPress={handlePress}
+      onLongPress={onLongPress}
+    >
+      <View style={styles.cardTop}>
+        <View style={styles.cardLeft}>
+          {selecting && (
+            <View style={[styles.checkbox, checked && { backgroundColor: theme.accent, borderColor: theme.accent }]}>
+              {checked && <Text style={styles.checkmark}>✓</Text>}
+            </View>
+          )}
+          <Text style={styles.sportIcon}>{sportIcon(activity.sport)}</Text>
+        </View>
+        <View style={styles.cardMeta}>
+          <Text style={styles.cardDate}>{date}</Text>
+          {activity.origin === 'remote'
+            ? <Text style={[styles.remoteBadge, { color: theme.accent, borderColor: theme.accent }]}>cloud</Text>
+            : !activity.synced_at && <Text style={styles.localBadge}>local</Text>
+          }
+        </View>
+      </View>
+      <Text style={styles.cardTitle} numberOfLines={1}>{activity.title}</Text>
+      <View style={styles.cardStats}>
+        {km   && <Stat label="km" value={km} />}
+        {elev != null && <Stat label="m↑" value={String(elev)} />}
+      </View>
+    </Pressable>
+  );
+}
+
+export function Stat({ label, value }: { label: string; value: string }) {
+  return (
+    <View style={styles.stat}>
+      <Text style={styles.statValue}>{value}</Text>
+      <Text style={styles.statLabel}>{label}</Text>
+    </View>
+  );
+}
+
+export function sportIcon(sport: string): string {
+  const icons: Record<string, string> = {
+    cycling: '🚴', running: '🏃', hiking: '🥾', swimming: '🏊', walking: '🚶',
+  };
+  return icons[sport] ?? '🏅';
+}
+
+const styles = StyleSheet.create({
+  card: {
+    backgroundColor: '#18181b', borderRadius: 12,
+    padding: 16, borderWidth: 1, borderColor: '#27272a',
+  },
+  cardTop:  { flexDirection: 'row', justifyContent: 'space-between', marginBottom: 6 },
+  cardLeft: { flexDirection: 'row', alignItems: 'center', gap: 10 },
+  sportIcon: { fontSize: 20 },
+  cardMeta: { flexDirection: 'row', alignItems: 'center', gap: 8 },
+  cardDate: { color: '#71717a', fontSize: 12 },
+  remoteBadge: {
+    fontSize: 10, borderWidth: 1,
+    borderRadius: 4, paddingHorizontal: 4,
+  },
+  localBadge: {
+    color: '#a1a1aa', fontSize: 10, borderWidth: 1,
+    borderColor: '#3f3f46', borderRadius: 4, paddingHorizontal: 4,
+  },
+  cardTitle:  { color: '#f4f4f5', fontSize: 15, fontWeight: '600', marginBottom: 10 },
+  cardStats:  { flexDirection: 'row', gap: 16 },
+  stat:       { flexDirection: 'row', alignItems: 'baseline', gap: 3 },
+  statValue:  { color: '#f4f4f5', fontSize: 16, fontWeight: '600' },
+  statLabel:  { color: '#71717a', fontSize: 12 },
+  checkbox: {
+    width: 20, height: 20, borderRadius: 4, borderWidth: 1.5,
+    borderColor: '#52525b', alignItems: 'center', justifyContent: 'center',
+  },
+  checkmark: { color: '#fff', fontSize: 12, fontWeight: '700' },
+});

mobile/db/queries.ts

@@ -74,6 +74,48 @@ export function useActivityCount(searchQuery = ''): number {
 
 export { PAGE_SIZE };
 
+export type ActivityFilter = {
+  sport: string;    // '' = all sports
+  dateFrom: string; // '' = no lower bound; ISO-like 'YYYY-MM-DDTHHMMSSZ' for comparison
+  sort: 'date' | 'distance' | 'elevation';
+};
+
+const SORT_SQL: Record<string, string> = {
+  date:      "json_extract(detail_json, '$.started_at') DESC",
+  distance:  "json_extract(detail_json, '$.distance_m') DESC",
+  elevation: "json_extract(detail_json, '$.elevation_gain_m') DESC",
+};
+
+export function useFilteredActivities(filter: ActivityFilter, limit = PAGE_SIZE): ActivitySummary[] {
+  const db = useSQLiteContext();
+  const order = SORT_SQL[filter.sort] ?? SORT_SQL.date;
+  return db.getAllSync<ActivitySummary>(`
+    SELECT
+      id, origin, synced_at,
+      json_extract(detail_json, '$.title')            AS title,
+      json_extract(detail_json, '$.sport')            AS sport,
+      json_extract(detail_json, '$.started_at')       AS started_at,
+      json_extract(detail_json, '$.distance_m')       AS distance_m,
+      json_extract(detail_json, '$.duration_s')       AS duration_s,
+      json_extract(detail_json, '$.elevation_gain_m') AS elevation_gain_m
+    FROM activities
+    WHERE (? = '' OR json_extract(detail_json, '$.sport') = ?)
+      AND (? = '' OR json_extract(detail_json, '$.started_at') >= ?)
+    ORDER BY ${order}
+    LIMIT ?
+  `, [filter.sport, filter.sport, filter.dateFrom, filter.dateFrom, limit]);
+}
+
+export function useFilteredCount(filter: ActivityFilter): number {
+  const db = useSQLiteContext();
+  const row = db.getFirstSync<{ n: number }>(`
+    SELECT COUNT(*) as n FROM activities
+    WHERE (? = '' OR json_extract(detail_json, '$.sport') = ?)
+      AND (? = '' OR json_extract(detail_json, '$.started_at') >= ?)
+  `, [filter.sport, filter.sport, filter.dateFrom, filter.dateFrom]);
+  return row?.n ?? 0;
+}
+
 export function useActivity(id: string): ActivityRow | null {
   const db = useSQLiteContext();
   return db.getFirstSync<ActivityRow>(