feat: crop save (save visible area at original resolution) v1.4.0

- Save visible area at original resolution as JPEG q90 (title bar button or Ctrl+S)
- Output name: original name + _HHmmss suffix; no overwrite, warning shown
- Active color effects baked in; rotation saves bounding box
- New: crop_save_service, l10n strings TR/EN, docs/plan-crop-save.md

pubspec.yaml

@@ -1,7 +1,7 @@
 name: imajviewer
 description: "Ultra-lightweight image viewer for Linux and Windows."
 publish_to: 'none'
-version: 1.3.2+7
+version: 1.4.0+8
 
 msix_config:
   display_name: ImajViewer
@@ -24,6 +24,7 @@ dependencies:
   file_picker: ^8.0.0
   path: ^1.9.0
   desktop_drop: ^0.7.1
+  image: ^4.0.0
   msix: ^3.18.0
   printing: ^5.13.4
   pdf: ^3.11.1