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/data/variety_repository.dart

@@ -455,6 +455,42 @@ class VarietyRepository {
     return id;
   }
 
+  /// Updates an existing lot's fields (LWW). The [quantity] and [harvestYear]
+  /// are set as given (null clears them).
+  Future<void> updateLot({
+    required String lotId,
+    required LotType type,
+    int? harvestYear,
+    Quantity? quantity,
+    String? storageLocation,
+  }) async {
+    final (_, updated) = _stamp();
+    await (_db.update(_db.lots)..where((l) => l.id.equals(lotId))).write(
+      LotsCompanion(
+        type: Value(type),
+        harvestYear: Value(harvestYear),
+        quantityKind: Value(quantity?.kind.name),
+        quantityPrecise: Value(quantity?.count?.toDouble()),
+        quantityLabel: Value(quantity?.label),
+        storageLocation: Value(storageLocation),
+        updatedAt: Value(updated),
+        lastAuthor: Value(nodeId),
+      ),
+    );
+  }
+
+  /// Soft-deletes a lot (tombstone); it leaves the variety's lot list.
+  Future<void> softDeleteLot(String lotId) async {
+    final (_, updated) = _stamp();
+    await (_db.update(_db.lots)..where((l) => l.id.equals(lotId))).write(
+      LotsCompanion(
+        isDeleted: const Value(true),
+        updatedAt: Value(updated),
+        lastAuthor: Value(nodeId),
+      ),
+    );
+  }
+
   /// Soft-deletes a variety (tombstone); it disappears from the inventory but
   /// the row survives for correct CRDT merges later.
   Future<void> softDeleteVariety(String id) async {

apps/app_seeds/lib/i18n/en.i18n.json

@@ -32,6 +32,7 @@
     "names": "Also known as",
     "notes": "Notes",
     "addLot": "Add lot",
+    "editLot": "Edit lot",
     "deleteConfirm": "Delete this seed?",
     "year": "Year {year}",
     "noYear": "Year unknown"

apps/app_seeds/lib/i18n/es.i18n.json

@@ -32,6 +32,7 @@
     "names": "También conocida como",
     "notes": "Notas",
     "addLot": "Añadir lote",
+    "editLot": "Editar lote",
     "deleteConfirm": "¿Eliminar esta semilla?",
     "year": "Año {year}",
     "noYear": "Año desconocido"

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

@@ -4,9 +4,9 @@
 /// To regenerate, run: `dart run slang`
 ///
 /// Locales: 2
-/// Strings: 182 (91 per locale)
+/// Strings: 184 (92 per locale)
 ///
-/// Built on 2026-07-08 at 08:39 UTC
+/// Built on 2026-07-08 at 09:07 UTC
 
 // coverage:ignore-file
 // ignore_for_file: type=lint, unused_import

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',

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

@@ -118,6 +118,7 @@ class _Translations$detail$es extends Translations$detail$en {
 	@override String get names => 'También conocida como';
 	@override String get notes => 'Notas';
 	@override String get addLot => 'Añadir lote';
+	@override String get editLot => 'Editar lote';
 	@override String get deleteConfirm => '¿Eliminar esta semilla?';
 	@override String year({required Object year}) => 'Año ${year}';
 	@override String get noYear => 'Año desconocido';
@@ -474,6 +475,7 @@ extension on TranslationsEs {
 			'detail.names' => 'También conocida como',
 			'detail.notes' => 'Notas',
 			'detail.addLot' => 'Añadir lote',
+			'detail.editLot' => 'Editar lote',
 			'detail.deleteConfirm' => '¿Eliminar esta semilla?',
 			'detail.year' => ({required Object year}) => 'Año ${year}',
 			'detail.noYear' => 'Año desconocido',

apps/app_seeds/lib/state/variety_detail_cubit.dart

@@ -62,6 +62,20 @@ class VarietyDetailCubit extends Cubit<VarietyDetailState> {
     quantity: quantity,
   );
 
+  Future<void> updateLot({
+    required String lotId,
+    required LotType type,
+    int? year,
+    Quantity? quantity,
+  }) => _repo.updateLot(
+    lotId: lotId,
+    type: type,
+    harvestYear: year,
+    quantity: quantity,
+  );
+
+  Future<void> deleteLot(String lotId) => _repo.softDeleteLot(lotId);
+
   Future<void> linkSpecies(String speciesId) =>
       _repo.linkSpecies(varietyId, speciesId);
 

apps/app_seeds/lib/ui/variety_detail_screen.dart

@@ -1,4 +1,3 @@
-import 'package:commons_core/commons_core.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 
@@ -100,7 +99,7 @@ class _DetailView extends StatelessWidget {
               _SectionTitle(t.detail.lots),
               TextButton.icon(
                 key: const Key('detail.addLot'),
-                onPressed: () => _showAddLotSheet(context, cubit),
+                onPressed: () => _showLotSheet(context, cubit),
                 icon: const Icon(Icons.add),
                 label: Text(t.detail.addLot),
               ),
@@ -111,7 +110,9 @@ class _DetailView extends StatelessWidget {
           else
             for (final lot in detail.lots)
               ListTile(
+                key: Key('lot.${lot.id}'),
                 contentPadding: EdgeInsets.zero,
+                onTap: () => _showLotSheet(context, cubit, existing: lot),
                 leading: lot.quantity == null
                     ? const Icon(Icons.inventory_2_outlined)
                     : QuantityKindIcon(lot.quantity!.kind, size: 28),
@@ -475,15 +476,20 @@ class _EditVarietySheetState extends State<_EditVarietySheet> {
   }
 }
 
-Future<void> _showAddLotSheet(BuildContext context, VarietyDetailCubit cubit) {
+Future<void> _showLotSheet(
+  BuildContext context,
+  VarietyDetailCubit cubit, {
+  VarietyLot? existing,
+}) {
   final t = context.t;
   final currentYear = DateTime.now().year;
   // Harvest years: current year down through the last four decades. Newest
   // first because a freshly harvested lot is the common case.
   final years = [for (var y = currentYear; y >= currentYear - 40; y--) y];
-  var selectedYear = currentYear;
+  var selectedYear = existing?.harvestYear ?? currentYear;
-  var selectedType = LotType.seed;
+  var selectedType = existing?.type ?? LotType.seed;
-  Quantity? selectedQuantity;
+  var selectedQuantity = existing?.quantity;
+  final editing = existing != null;
   return showModalBottomSheet<void>(
     context: context,
     isScrollControlled: true,
@@ -499,9 +505,25 @@ Future<void> _showAddLotSheet(BuildContext context, VarietyDetailCubit cubit) {
           mainAxisSize: MainAxisSize.min,
           crossAxisAlignment: CrossAxisAlignment.stretch,
           children: [
-            Text(
+            Row(
-              t.addLot.title,
+              children: [
-              style: Theme.of(sheetContext).textTheme.titleLarge,
+                Expanded(
+                  child: Text(
+                    editing ? t.detail.editLot : t.addLot.title,
+                    style: Theme.of(sheetContext).textTheme.titleLarge,
+                  ),
+                ),
+                if (editing)
+                  IconButton(
+                    key: const Key('lot.delete'),
+                    icon: const Icon(Icons.delete_outline),
+                    tooltip: t.common.delete,
+                    onPressed: () {
+                      cubit.deleteLot(existing.id);
+                      Navigator.of(sheetContext).pop();
+                    },
+                  ),
+              ],
             ),
             const SizedBox(height: 12),
             LotTypeSelector(
@@ -549,11 +571,20 @@ Future<void> _showAddLotSheet(BuildContext context, VarietyDetailCubit cubit) {
                 FilledButton(
                   key: const Key('addLot.save'),
                   onPressed: () {
-                    cubit.addLot(
+                    if (editing) {
-                      type: selectedType,
+                      cubit.updateLot(
-                      year: selectedYear,
+                        lotId: existing.id,
-                      quantity: selectedQuantity,
+                        type: selectedType,
-                    );
+                        year: selectedYear,
+                        quantity: selectedQuantity,
+                      );
+                    } else {
+                      cubit.addLot(
+                        type: selectedType,
+                        year: selectedYear,
+                        quantity: selectedQuantity,
+                      );
+                    }
                     Navigator.of(sheetContext).pop();
                   },
                   child: Text(t.common.save),

apps/app_seeds/test/data/variety_detail_test.dart

@@ -4,6 +4,7 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:tane/data/species_repository.dart';
 import 'package:tane/data/variety_repository.dart';
 import 'package:tane/db/database.dart';
+import 'package:tane/db/enums.dart';
 
 import '../support/test_support.dart';
 
@@ -139,4 +140,35 @@ void main() {
 
     await queue.cancel();
   });
+
+  test('updateLot changes a lot\'s year, type and quantity', () async {
+    final id = await repo.addQuickVariety(label: 'Maize');
+    final lotId = await repo.addLot(
+      varietyId: id,
+      harvestYear: 2020,
+      quantity: const Quantity(kind: QuantityKind.packet, count: 1),
+    );
+
+    await repo.updateLot(
+      lotId: lotId,
+      type: LotType.plant,
+      harvestYear: 2024,
+      quantity: const Quantity(kind: QuantityKind.plant, count: 3),
+    );
+
+    final lot = (await repo.watchVariety(id).first)!.lots.single;
+    expect(lot.type, LotType.plant);
+    expect(lot.harvestYear, 2024);
+    expect(lot.quantity?.kind, QuantityKind.plant);
+    expect(lot.quantity?.count, 3);
+  });
+
+  test('softDeleteLot removes the lot from the variety', () async {
+    final id = await repo.addQuickVariety(label: 'Maize');
+    final lotId = await repo.addLot(varietyId: id, harvestYear: 2024);
+
+    await repo.softDeleteLot(lotId);
+
+    expect((await repo.watchVariety(id).first)!.lots, isEmpty);
+  });
 }

apps/app_seeds/test/ui/variety_detail_screen_test.dart

@@ -200,4 +200,59 @@ void main() {
     expect(find.text('90%'), findsOneWidget); // germination badge on the lot
     await disposeTree(tester);
   });
+
+  testWidgets('editing a lot updates its line', (tester) async {
+    final repo = newTestRepository(db);
+    final id = await repo.addQuickVariety(label: 'Maize');
+    await repo.addLot(
+      varietyId: id,
+      harvestYear: 2020,
+      quantity: const Quantity(kind: QuantityKind.packet, count: 1),
+    );
+
+    await tester.pumpWidget(
+      wrapDetail(
+        repository: repo,
+        varietyId: id,
+        species: newTestSpeciesRepository(db),
+      ),
+    );
+    await tester.pumpAndSettle();
+
+    await tester.tap(find.text('Year 2020 · 1 packet')); // open the lot
+    await tester.pumpAndSettle();
+
+    await tester.tap(find.byKey(const Key('addLot.year')));
+    await tester.pumpAndSettle();
+    await tester.tap(find.text('2024').last);
+    await tester.pumpAndSettle();
+    await tester.tap(find.byKey(const Key('addLot.save')));
+    await tester.pumpAndSettle();
+
+    expect(find.text('Year 2024 · 1 packet'), findsOneWidget);
+    await disposeTree(tester);
+  });
+
+  testWidgets('deleting a lot removes it', (tester) async {
+    final repo = newTestRepository(db);
+    final id = await repo.addQuickVariety(label: 'Maize');
+    await repo.addLot(varietyId: id, harvestYear: 2020);
+
+    await tester.pumpWidget(
+      wrapDetail(
+        repository: repo,
+        varietyId: id,
+        species: newTestSpeciesRepository(db),
+      ),
+    );
+    await tester.pumpAndSettle();
+
+    await tester.tap(find.textContaining('Year 2020')); // open the lot
+    await tester.pumpAndSettle();
+    await tester.tap(find.byKey(const Key('lot.delete')));
+    await tester.pumpAndSettle();
+
+    expect(find.text('No lots yet.'), findsOneWidget);
+    await disposeTree(tester);
+  });
 }