Give the map the whole screen and move the credits into settings

Drops the app bar, moves settings onto the map with the other controls, and
takes the attribution bar off the main screen.

The app bar held only the app name — which the launcher already shows — and one
action, so removing it hands its height to the map rather than leaving an empty
strip. The settings button joins search and recentre in the column over the
map, where the rest of the controls that act on the map already live.

The attribution needed checking before it could move, because it is a licence
obligation rather than a layout choice. The OSMF guidelines settle it: for a
browsable map the credit does not have to be permanently visible, provided
"the user must still be able to find the licence information if they look for
it, for example from an '(i)' button in the corner of the map or an 'About'
option in a menu". Map to settings to "Fonti e licenze" is exactly that, and
MapLibre's own (i) control now sits in the map's top-right corner as a second
route — it had been landing underneath the new button column.

Two things had to follow the bar rather than disappear with it. The radar
manifest carries its own credit for the frames on screen, set by whoever
published them and absent from the region config, so the Sources screen now
shows it alongside the configured attributions. And the settings entry that
leads there carries a subtitle saying what it holds, because "Fonti e licenze"
alone does not tell a reader that this is where the licence information went.

settings_screen_test asserts that entry exists and opens the screen. Removing
it would be a licence breach, so it should fail the build rather than ship
quietly.

Verified on the emulator: no title bar, the map runs to the top with the demo
notice above it, the three controls stack bottom-right without colliding with
the (i), and settings shows the sources entry with its subtitle.

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

Nuvolari/app/lib/features/settings/settings_screen.dart

@@ -97,9 +97,14 @@ class _SettingsScreenState extends ConsumerState<SettingsScreen> {
           ),
 
           const Divider(),
+          // The map no longer carries a permanent credit line, so this is the
+          // route the attribution guidelines require. It must stay easy to
+          // find: do not bury it deeper or drop the subtitle that says what it
+          // holds.
           ListTile(
             leading: const Icon(Icons.info_outline),
             title: Text(l10n.sourcesTitle),
+            subtitle: Text(l10n.settingsSourcesHint),
             trailing: const Icon(Icons.chevron_right),
             onTap: () => Navigator.of(context).push(
               MaterialPageRoute<void>(builder: (_) => const SourcesScreen()),