fix(ui): pad Node Details content above the bottom nav bar

The scroll column ended at 16.dp, so the last card sat behind the
nav bar now that the bar is visible on this screen. Use the same
88.dp bottom clearance as the other nav-visible screens.

Author: torlando-tech

app/src/main/java/network/columba/app/ui/screens/AnnounceDetailScreen.kt

@@ -201,7 +201,10 @@ fun AnnounceDetailScreen(
                         .fillMaxSize()
                         .padding(paddingValues)
                         .verticalScroll(rememberScrollState())
-                        .padding(16.dp),
+                        // The outer bottom nav bar is visible on this screen, so
+                        // clear its height (same 88.dp convention as other
+                        // nav-visible screens) for the last card.
+                        .padding(start = 16.dp, end = 16.dp, top = 16.dp, bottom = 88.dp),
                 verticalArrangement = Arrangement.spacedBy(16.dp),
             ) {
                 // Identicon header