feat(inventory): edit and delete existing lots

Lots could only be created; now they can be edited and removed:
- Repository: updateLot (LWW) + softDeleteLot (tombstone).
- Cubit: updateLot / deleteLot.
- The add-lot sheet is now a shared add/edit sheet — tapping a lot opens it
  prefilled (type, year, quantity), with a trash action to delete. The reactive
  detail view refreshes on save/delete.

Tests: repo updateLot/softDeleteLot + widget edit-lot and delete-lot. 42 green.

apps/app_seeds/lib/i18n/strings_en.g.dart

@@ -168,6 +168,9 @@ class Translations$detail$en {
 	/// en: 'Add lot'
 	String get addLot => 'Add lot';
 
+	/// en: 'Edit lot'
+	String get editLot => 'Edit lot';
+
 	/// en: 'Delete this seed?'
 	String get deleteConfirm => 'Delete this seed?';
 
@@ -658,6 +661,7 @@ extension on Translations {
 			'detail.names' => 'Also known as',
 			'detail.notes' => 'Notes',
 			'detail.addLot' => 'Add lot',
+			'detail.editLot' => 'Edit lot',
 			'detail.deleteConfirm' => 'Delete this seed?',
 			'detail.year' => ({required Object year}) => 'Year ${year}',
 			'detail.noYear' => 'Year unknown',