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.lock

@@ -198,7 +198,7 @@ packages:
     source: hosted
     version: "4.1.2"
   image:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: image
       sha256: "6300175e00616bbc832e2fc91bfa4d776af5402c81c7151bee6905bb08473c52"