feat: default bottom bar to Home, Messages, Wallet, Browser, Notifications

Change the default bottom navigation for new users from
Home/Messages/Shorts/Discover/Favorite Algo Feeds/Notifications to
Home/Messages/Wallet/Browser/Notifications. The Browser entry is gated
to API 30+ since it renders a cross-process surface, matching the
drawer's existing gating.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WRdmDri69mLJiHpJQpJU73

amethyst/src/main/java/com/vitorpamplona/amethyst/ui/navigation/bottombars/NavBarItem.kt

@@ -376,12 +376,13 @@ val NavBarCatalog: Map<NavBarItem, NavBarItemDef> =
     )
 
 val DefaultBottomBarItems: List<NavBarItem> =
-    listOf(
+    listOfNotNull(
         NavBarItem.HOME,
         NavBarItem.MESSAGES,
-        NavBarItem.VIDEO,
-        NavBarItem.DISCOVER,
-        NavBarItem.FAVORITE_ALGO_FEEDS,
+        NavBarItem.WALLET,
+        // The embedded browser renders a cross-process surface (SurfaceControlViewHost), which needs
+        // API 30+. Below that the item is dropped so the feature can't be pinned or opened.
+        NavBarItem.BROWSER.takeIf { Build.VERSION.SDK_INT >= Build.VERSION_CODES.R },
         NavBarItem.NOTIFICATIONS,
     )