Add map/list toggle on the start screen; fix text contrast over map

The "found N places" overlay text (and the checking/no-places states)
used the theme's default light text color, which washed out against
the now-real, mostly light-colored OSM map tiles. Fixed with a fixed
dark color (Mocha.Crust) for text overlaid on the map.

Added a toggle button (top bar, visible once places are found) that
switches the start screen between the map and a plain list preview of
the found places (reusing PlaceCard in its neutral/UPCOMING state) —
lets the user see what's "ready to read" before committing to Start.

Verified: testDebugUnitTest passes, assembleDebug produces a working
APK, sent to Telegram.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

android/app/src/main/res/values-ru/strings.xml

@@ -19,6 +19,8 @@
     <string name="map_places_found">Найдено мест поблизости: %1$d (в радиусе %2$d м)</string>
     <string name="map_start">Начать</string>
     <string name="map_no_places_nearby">В радиусе 10 км ничего не нашлось.</string>
+    <string name="map_show_list">Показать список</string>
+    <string name="map_show_map">Показать карту</string>
 
     <string name="guide_no_places_nearby">Поблизости пока не найдено интересных мест.</string>
     <string name="guide_places_count">Мест поблизости: %1$d</string>