feat: update app structure and improve user experience; refactor media handling and enhance NAS integration

src/screens/SearchScreen.js

@@ -76,7 +76,9 @@ const SearchScreen = ({ route }) => {
         <View style={styles.emptyContainer}>
           <Text style={styles.emptyIcon}>🔍</Text>
           <Text style={[styles.emptyTitle, { color: theme.text }]}>Search your photos</Text>
-          <Text style={[styles.emptyText, { color: theme.textSecondary }]}>Search by title or description</Text>
+          <Text style={[styles.emptyText, { color: theme.textSecondary }]}>
+            Search by filename and indexed metadata (bag-of-words style matching)
+          </Text>
         </View>
       )}