feat(ui): finales 5-Tab-Layout (Player/Bibliothek/Playlisten/Suche/Settings)

- "Zuletzt hinzugefügt" aus dem alten HomeScreen in die Bibliothek verschoben:
  horizontal scrollende Leiste über der vollen Songliste, nur sichtbar wenn
  nicht leer und nicht gerade gescannt wird
- home_screen.dart entfernt (Funktionalität jetzt Teil von LibraryScreen)
- HomeShell-Tabs auf die finale Struktur umgestellt: NowPlayingScreen an
  Position 0, Playlisten- und Settings-Platzhalter an ihren finalen
  Positionen (werden in späteren Tasks durch echte Screens ersetzt)
- BottomNavigationBar-Icons/Labels an die neue Reihenfolge angepasst
- MiniPlayer wird ausgeblendet, solange der Now-Playing-Tab aktiv ist
  (redundant, da der Tab selbst schon die volle Wiedergabe-Ansicht zeigt)

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

lib/home_screen.dart

@@ -1,76 +0,0 @@
-import 'package:flutter/material.dart';
-import 'package:provider/provider.dart';
-
-import 'library/database.dart';
-import 'library/library_service.dart';
-import 'library/song_list.dart';
-
-/// Startseite: zuletzt hinzugefügte Songs, sonst ein Willkommens-Hinweis.
-class HomeScreen extends StatelessWidget {
-  const HomeScreen({super.key});
-
-  @override
-  Widget build(BuildContext context) {
-    final db = context.read<MeloDb>();
-    return Scaffold(
-      appBar: AppBar(
-        title: const Text('Melo',
-            style: TextStyle(fontWeight: FontWeight.bold, fontSize: 26)),
-      ),
-      body: StreamBuilder<List<Song>>(
-        stream: db.watchRecent(),
-        builder: (context, snapshot) {
-          if (snapshot.hasError) {
-            return Center(
-              child: Text('Fehler: ${snapshot.error}',
-                  style: const TextStyle(color: Colors.white54)),
-            );
-          }
-          final songs = snapshot.data ?? const [];
-          if (songs.isEmpty) return const _Welcome();
-          return Column(
-            crossAxisAlignment: CrossAxisAlignment.start,
-            children: [
-              const Padding(
-                padding: EdgeInsets.fromLTRB(16, 8, 16, 8),
-                child: Text('Zuletzt hinzugefügt',
-                    style:
-                        TextStyle(fontSize: 18, fontWeight: FontWeight.w600)),
-              ),
-              Expanded(child: SongList(songs)),
-            ],
-          );
-        },
-      ),
-    );
-  }
-}
-
-class _Welcome extends StatelessWidget {
-  const _Welcome();
-
-  @override
-  Widget build(BuildContext context) {
-    final lib = context.read<LibraryService>();
-    return Center(
-      child: Column(
-        mainAxisSize: MainAxisSize.min,
-        children: [
-          const Icon(Icons.music_note, size: 72, color: Colors.white24),
-          const SizedBox(height: 12),
-          const Text('Willkommen bei Melo',
-              style: TextStyle(fontSize: 18)),
-          const SizedBox(height: 4),
-          const Text('Füge deine Musik hinzu, um loszulegen',
-              style: TextStyle(color: Colors.white54)),
-          const SizedBox(height: 20),
-          FilledButton.icon(
-            icon: const Icon(Icons.create_new_folder_outlined),
-            label: Text(addMusicLabel),
-            onPressed: lib.pickFolderAndScan,
-          ),
-        ],
-      ),
-    );
-  }
-}

lib/library/library_screen.dart

@@ -1,10 +1,13 @@
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
+import '../player/audio_handler.dart';
+import '../shared/cover.dart';
 import 'database.dart';
 import 'library_service.dart';
 import 'permissions.dart';
 import 'song_list.dart';
+import 'song_media.dart';
 
 class LibraryScreen extends StatelessWidget {
   const LibraryScreen({super.key});
@@ -69,6 +72,14 @@ class LibraryScreen extends StatelessWidget {
                 ],
               ),
             ),
+          StreamBuilder<List<Song>>(
+            stream: db.watchRecent(limit: 10),
+            builder: (context, snapshot) {
+              final recent = snapshot.data ?? const [];
+              if (recent.isEmpty || lib.scanning) return const SizedBox.shrink();
+              return _RecentlyAdded(songs: recent);
+            },
+          ),
           Expanded(
             child: StreamBuilder<List<Song>>(
               stream: db.watchSongs(),
@@ -93,6 +104,76 @@ class LibraryScreen extends StatelessWidget {
   }
 }
 
+/// Horizontal scrollende Leiste mit den zuletzt hinzugefügten Songs.
+class _RecentlyAdded extends StatelessWidget {
+  const _RecentlyAdded({required this.songs});
+  final List<Song> songs;
+
+  @override
+  Widget build(BuildContext context) {
+    final handler = context.read<MeloAudioHandler>();
+    return Column(
+      crossAxisAlignment: CrossAxisAlignment.start,
+      children: [
+        const Padding(
+          padding: EdgeInsets.fromLTRB(16, 8, 16, 8),
+          child: Text('Zuletzt hinzugefügt',
+              style: TextStyle(fontSize: 18, fontWeight: FontWeight.w600)),
+        ),
+        SizedBox(
+          height: 140,
+          child: ListView.builder(
+            scrollDirection: Axis.horizontal,
+            padding: const EdgeInsets.symmetric(horizontal: 16),
+            itemCount: songs.length,
+            itemBuilder: (context, i) {
+              final s = songs[i];
+              return Padding(
+                padding: const EdgeInsets.only(right: 12),
+                child: SizedBox(
+                  width: 96,
+                  child: InkWell(
+                    onTap: () async {
+                      try {
+                        await playSongs(handler, songs, i);
+                      } catch (e) {
+                        if (context.mounted) {
+                          ScaffoldMessenger.of(context).showSnackBar(
+                            SnackBar(
+                                content: Text('Wiedergabe fehlgeschlagen: $e')),
+                          );
+                        }
+                      }
+                    },
+                    child: Column(
+                      crossAxisAlignment: CrossAxisAlignment.start,
+                      children: [
+                        CoverImage(
+                          artUri:
+                              s.coverPath != null ? Uri.file(s.coverPath!) : null,
+                          size: 96,
+                          radius: 8,
+                        ),
+                        const SizedBox(height: 4),
+                        Text(
+                          s.title,
+                          maxLines: 1,
+                          overflow: TextOverflow.ellipsis,
+                          style: const TextStyle(fontSize: 12),
+                        ),
+                      ],
+                    ),
+                  ),
+                ),
+              );
+            },
+          ),
+        ),
+      ],
+    );
+  }
+}
+
 class _Empty extends StatelessWidget {
   const _Empty();
 

lib/main.dart

@@ -2,7 +2,6 @@ import 'package:audio_service/audio_service.dart';
 import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 
-import 'home_screen.dart';
 import 'library/database.dart';
 import 'library/library_screen.dart';
 import 'library/library_service.dart';
@@ -10,6 +9,7 @@ import 'library/playlist_service.dart';
 import 'library/search_screen.dart';
 import 'player/audio_handler.dart';
 import 'player/mini_player.dart';
+import 'player/now_playing_screen.dart';
 import 'shared/theme.dart';
 
 late final MeloAudioHandler _handler;
@@ -66,11 +66,11 @@ class _HomeShellState extends State<HomeShell> {
   int _index = 0;
 
   static const _tabs = <Widget>[
-    HomeScreen(),
+    NowPlayingScreen(),
     LibraryScreen(),
+    _Placeholder(label: 'Playlisten', hint: 'Kommt in Kürze'),
     SearchScreen(),
-    _Placeholder(label: 'Playlists', hint: 'Playlists & Favoriten (P3)'),
-    _Placeholder(label: 'Recaps', hint: 'Wöchentlich/Monatlich/Jährlich (P5)'),
+    _Placeholder(label: 'Settings', hint: 'Kommt in Kürze'),
   ];
 
   @override
@@ -79,20 +79,21 @@ class _HomeShellState extends State<HomeShell> {
       body: Column(
         children: [
           Expanded(child: IndexedStack(index: _index, children: _tabs)),
-          const MiniPlayer(),
+          if (_index != 0) const MiniPlayer(),
         ],
       ),
       bottomNavigationBar: BottomNavigationBar(
         currentIndex: _index,
         onTap: (i) => setState(() => _index = i),
         items: const [
-          BottomNavigationBarItem(icon: Icon(Icons.home), label: 'Home'),
+          BottomNavigationBarItem(
+              icon: Icon(Icons.play_circle_outline), label: 'Player'),
           BottomNavigationBarItem(
               icon: Icon(Icons.library_music), label: 'Bibliothek'),
-          BottomNavigationBarItem(icon: Icon(Icons.search), label: 'Suche'),
           BottomNavigationBarItem(
-              icon: Icon(Icons.playlist_play), label: 'Playlists'),
-          BottomNavigationBarItem(icon: Icon(Icons.bar_chart), label: 'Recaps'),
+              icon: Icon(Icons.playlist_play), label: 'Playlisten'),
+          BottomNavigationBarItem(icon: Icon(Icons.search), label: 'Suche'),
+          BottomNavigationBarItem(icon: Icon(Icons.settings), label: 'Settings'),
         ],
       ),
     );