chore(branding): Anzeigename 'Holzleitner Auslieferung' + Launcher-Icon

- Android android:label, iOS CFBundleDisplayName, MaterialApp.title -> 'Holzleitner Auslieferung'
- flutter_launcher_icons (assets/launch_icon.png) als Dev-Dep + Config

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

ios/Runner/Info.plist

@@ -7,7 +7,7 @@
 	<key>CFBundleDevelopmentRegion</key>
 	<string>$(DEVELOPMENT_LANGUAGE)</string>
 	<key>CFBundleDisplayName</key>
-	<string>Hl Lieferservice</string>
+	<string>Holzleitner Auslieferung</string>
 	<key>CFBundleExecutable</key>
 	<string>$(EXECUTABLE_NAME)</string>
 	<key>CFBundleIdentifier</key>