added support for simultan downloads in files and talk, support for background downloads, enhanced loading in files with retry

lib/view/pages/talk/widgets/chat_textfield.dart

@@ -13,6 +13,7 @@ import '../../../../state/app/modules/chat/bloc/chat_bloc.dart';
 import '../../../../state/app/modules/settings/bloc/settings_cubit.dart';
 import '../../../../widget/async_action_button.dart';
 import '../../../../widget/details_bottom_sheet.dart';
+import '../../../../widget/downloads/download_tray.dart';
 import '../../../../widget/emoji_picker_dialog.dart';
 import '../../../../widget/file_pick.dart';
 import '../../../../widget/focus_behaviour.dart';
@@ -34,8 +35,17 @@ class _ChatTextfieldState extends State<ChatTextfield> {
   final TextEditingController _textBoxController = TextEditingController();
   final AsyncActionController _sendController = AsyncActionController();
   final FocusNode _focusNode = FocusNode();
+  final GlobalKey _sizeKey = GlobalKey();
   String? _sendError;
 
+  /// Publishes the input bar's measured height so the downloads chip floats
+  /// above it instead of covering it.
+  void _publishHeight() {
+    if (!mounted) return;
+    final height = _sizeKey.currentContext?.size?.height;
+    if (height != null) downloadChipBottomObstruction.value = height;
+  }
+
   void share(List<String> uploadedRemotePaths) {
     shareFilesToChat(
       token: widget.sendToToken,
@@ -104,6 +114,7 @@ class _ChatTextfieldState extends State<ChatTextfield> {
 
   @override
   void dispose() {
+    downloadChipBottomObstruction.value = 0;
     _sendController.dispose();
     _focusNode.dispose();
     super.dispose();
@@ -236,7 +247,9 @@ class _ChatTextfieldState extends State<ChatTextfield> {
       }
     }
 
+    WidgetsBinding.instance.addPostFrameCallback((_) => _publishHeight());
     return Stack(
+      key: _sizeKey,
       children: <Widget>[
         Align(
           alignment: Alignment.bottomLeft,