feat: Refactor export functionality, add new translations

lib/features/document_scan/view/widgets/export_scans_dialog.dart

@@ -0,0 +1,88 @@
+import 'package:flutter/material.dart';
+import 'package:flutter/widgets.dart';
+import 'package:intl/intl.dart';
+import 'package:paperless_mobile/core/widgets/dialog_utils/dialog_cancel_button.dart';
+import 'package:paperless_mobile/core/widgets/dialog_utils/dialog_confirm_button.dart';
+import 'package:paperless_mobile/generated/l10n/app_localizations.dart';
+
+class ExportScansDialog extends StatefulWidget {
+  const ExportScansDialog({super.key});
+
+  @override
+  State<ExportScansDialog> createState() => _ExportScansDialogState();
+}
+
+class _ExportScansDialogState extends State<ExportScansDialog> {
+  final _formKey = GlobalKey<FormState>();
+  String? _filename;
+  late String _placeholder;
+
+  @override
+  void initState() {
+    super.initState();
+    final date = DateFormat("yyyy_MM_ddThhmmss").format(DateTime.now());
+    _placeholder = "paperless_mobile_scan_$date";
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return AlertDialog(
+      insetPadding: EdgeInsets.all(8),
+      title: Text(S.of(context)!.exportScansToPdf),
+      content: Form(
+        key: _formKey,
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          crossAxisAlignment: CrossAxisAlignment.start,
+          children: [
+            Text(S.of(context)!.allScansWillBeMerged),
+            SizedBox(height: 16),
+            TextFormField(
+              onSaved: (newValue) {
+                _filename = newValue;
+              },
+              autofocus: true,
+              autovalidateMode: AutovalidateMode.onUserInteraction,
+              validator: (value) {
+                final matches = RegExp(r'[<>:"/\|?*]').allMatches(value!);
+                if (matches.isNotEmpty) {
+                  final illegalCharacters = matches
+                      .map((match) => match.group(0))
+                      .toList()
+                      .toSet()
+                      .join(" ");
+                  return S
+                      .of(context)!
+                      .invalidFilenameCharacter(illegalCharacters);
+                }
+
+                return null;
+              },
+              decoration: InputDecoration(
+                labelText: S.of(context)!.fileName,
+                errorMaxLines: 5,
+                suffixText: ".pdf",
+                hintText: _placeholder,
+              ),
+            ),
+          ],
+        ),
+      ),
+      actions: [
+        const DialogCancelButton(),
+        DialogConfirmButton(
+          label: S.of(context)!.export,
+          onPressed: () async {
+            if (_formKey.currentState?.validate() ?? false) {
+              _formKey.currentState?.save();
+              final effectiveFilename = (_filename?.trim().isEmpty ?? true)
+                  ? _placeholder
+                  : _filename;
+              Navigator.pop(context, effectiveFilename);
+            }
+          },
+        ),
+      ],
+    );
+  }
+}

lib/features/document_scan/view/widgets/scanned_image_item.dart

@@ -61,7 +61,7 @@ class _ScannedImageItemState extends State<ScannedImageItem> {
                         width: double.infinity,
                         height: 100,
                         child: FittedBox(
-                          fit: BoxFit.fill,
+                          fit: BoxFit.cover,
                           clipBehavior: Clip.antiAliasWithSaveLayer,
                           alignment: Alignment.center,
                           child: Image.file(