feat(block1): germination tests per lot with derived rate

Record germination tests on a lot and surface the result.

- GerminationEntry model with a derived rate (germinated / sample). VarietyLot
  carries its tests (most-recent first) and exposes latestGerminationRate.
- VarietyRepository.addGerminationTest; watchVariety now also re-emits on
  germination-test changes, so the detail refreshes live.
- Detail UI: each lot shows a germination % badge and a grass action that opens
  a sheet listing past tests and adding a new one (germinated + sample size).
  i18n strings (ES/EN).

Tests: derived-rate + reactivity at the repository, and a widget test for the
record-test → badge flow. Full suite: 35 passing, 0 skipped.

apps/app_seeds/lib/data/variety_repository.dart

@@ -18,22 +18,63 @@ class VarietyListItem extends Equatable {
   List<Object?> get props => [id, label, category];
 }
 
-/// One held batch of a variety, for the detail view.
+/// One germination test on a lot; [rate] is derived (0..1), null when it can't
+/// be computed.
+class GerminationEntry extends Equatable {
+  const GerminationEntry({
+    required this.id,
+    this.testedOn,
+    this.sampleSize,
+    this.germinatedCount,
+    this.notes,
+  });
+
+  final String id;
+  final int? testedOn; // ms since epoch
+  final int? sampleSize;
+  final int? germinatedCount;
+  final String? notes;
+
+  double? get rate {
+    final sample = sampleSize;
+    final germinated = germinatedCount;
+    if (sample == null || sample <= 0 || germinated == null) return null;
+    return germinated / sample;
+  }
+
+  @override
+  List<Object?> get props => [id, testedOn, sampleSize, germinatedCount, notes];
+}
+
+/// One held batch of a variety, for the detail view. [germinationTests] are
+/// ordered most-recent first, so `germinationTests.first` is the latest.
 class VarietyLot extends Equatable {
   const VarietyLot({
     required this.id,
     this.harvestYear,
     this.quantity,
     this.storageLocation,
+    this.germinationTests = const [],
   });
 
   final String id;
   final int? harvestYear;
   final Quantity? quantity;
   final String? storageLocation;
+  final List<GerminationEntry> germinationTests;
+
+  /// The most recent germination rate (0..1), or null if there are no tests.
+  double? get latestGerminationRate =>
+      germinationTests.isEmpty ? null : germinationTests.first.rate;
 
   @override
-  List<Object?> get props => [id, harvestYear, quantity, storageLocation];
+  List<Object?> get props => [
+    id,
+    harvestYear,
+    quantity,
+    storageLocation,
+    germinationTests,
+  ];
 }
 
 /// The full detail of one variety (identity + its lots, names and first photo).
@@ -197,6 +238,8 @@ class VarietyRepository {
       (_db.select(
         _db.attachments,
       )..where((a) => a.parentId.equals(id))).watch().map((_) {}),
+      // Coarse: any germination-test change re-emits (catalog of tests is tiny).
+      _db.select(_db.germinationTests).watch().map((_) {}),
     ]);
     return triggers.asyncMap((_) => _loadVariety(id));
   }
@@ -221,6 +264,30 @@ class VarietyRepository {
               ..where((l) => l.varietyId.equals(id) & l.isDeleted.equals(false))
               ..orderBy([(l) => OrderingTerm.desc(l.harvestYear)]))
             .get();
+
+    final lotIds = lots.map((l) => l.id).toList();
+    final testsByLot = <String, List<GerminationEntry>>{};
+    if (lotIds.isNotEmpty) {
+      final tests =
+          await (_db.select(_db.germinationTests)
+                ..where((g) => g.lotId.isIn(lotIds) & g.isDeleted.equals(false))
+                ..orderBy([(g) => OrderingTerm.desc(g.testedOn)]))
+              .get();
+      for (final t in tests) {
+        testsByLot
+            .putIfAbsent(t.lotId, () => [])
+            .add(
+              GerminationEntry(
+                id: t.id,
+                testedOn: t.testedOn,
+                sampleSize: t.sampleSize,
+                germinatedCount: t.germinatedCount,
+                notes: t.notes,
+              ),
+            );
+      }
+    }
+
     final names = await (_db.select(
       _db.varietyVernacularNames,
     )..where((n) => n.varietyId.equals(id) & n.isDeleted.equals(false))).get();
@@ -243,7 +310,7 @@ class VarietyRepository {
       notes: v.notes,
       speciesId: v.speciesId,
       scientificName: scientificName,
-      lots: lots.map(_toLot).toList(),
+      lots: lots.map((l) => _toLot(l, testsByLot[l.id] ?? const [])).toList(),
       vernacularNames: names.map((n) => n.name).toList(),
       photo: photos.isEmpty ? null : photos.first.bytes,
     );
@@ -337,7 +404,35 @@ class VarietyRepository {
     );
   }
 
-  VarietyLot _toLot(Lot l) {
+  /// Records a germination test for a lot. Returns the new test id.
+  Future<String> addGerminationTest({
+    required String lotId,
+    int? testedOn,
+    int? sampleSize,
+    int? germinatedCount,
+    String? notes,
+  }) async {
+    final (created, updated) = _stamp();
+    final id = idGen.newId();
+    await _db
+        .into(_db.germinationTests)
+        .insert(
+          GerminationTestsCompanion.insert(
+            id: id,
+            lotId: lotId,
+            createdAt: created,
+            updatedAt: updated,
+            lastAuthor: nodeId,
+            testedOn: Value(testedOn),
+            sampleSize: Value(sampleSize),
+            germinatedCount: Value(germinatedCount),
+            notes: Value(notes),
+          ),
+        );
+    return id;
+  }
+
+  VarietyLot _toLot(Lot l, List<GerminationEntry> germinationTests) {
     final hasQuantity =
         l.quantityKind != null ||
         l.quantityPrecise != null ||
@@ -346,6 +441,7 @@ class VarietyRepository {
       id: l.id,
       harvestYear: l.harvestYear,
       storageLocation: l.storageLocation,
+      germinationTests: germinationTests,
       quantity: hasQuantity
           ? Quantity(
               kind: _parseKind(l.quantityKind),

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

@@ -35,6 +35,14 @@
     "year": "Year {year}",
     "noYear": "Year unknown"
   },
+  "germination": {
+    "title": "Germination",
+    "add": "Add test",
+    "sampleSize": "Sample size",
+    "germinated": "Germinated",
+    "none": "No germination tests yet.",
+    "result": "{percent}%"
+  },
   "editVariety": {
     "title": "Edit seed",
     "name": "Name",

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

@@ -35,6 +35,14 @@
     "year": "Año {year}",
     "noYear": "Año desconocido"
   },
+  "germination": {
+    "title": "Germinación",
+    "add": "Añadir prueba",
+    "sampleSize": "Muestra",
+    "germinated": "Germinadas",
+    "none": "Aún no hay pruebas de germinación.",
+    "result": "{percent}%"
+  },
   "editVariety": {
     "title": "Editar semilla",
     "name": "Nombre",

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

@@ -4,9 +4,9 @@
 /// To regenerate, run: `dart run slang`
 ///
 /// Locales: 2
-/// Strings: 106 (53 per locale)
+/// Strings: 118 (59 per locale)
 ///
-/// Built on 2026-07-07 at 19:21 UTC
+/// Built on 2026-07-07 at 19:58 UTC
 
 // coverage:ignore-file
 // ignore_for_file: type=lint, unused_import

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

@@ -45,6 +45,7 @@ class Translations with BaseTranslations<AppLocale, Translations> {
 	late final Translations$inventory$en inventory = Translations$inventory$en.internal(_root);
 	late final Translations$quickAdd$en quickAdd = Translations$quickAdd$en.internal(_root);
 	late final Translations$detail$en detail = Translations$detail$en.internal(_root);
+	late final Translations$germination$en germination = Translations$germination$en.internal(_root);
 	late final Translations$editVariety$en editVariety = Translations$editVariety$en.internal(_root);
 	late final Translations$addLot$en addLot = Translations$addLot$en.internal(_root);
 	late final Translations$quantityKind$en quantityKind = Translations$quantityKind$en.internal(_root);
@@ -173,6 +174,33 @@ class Translations$detail$en {
 	String get noYear => 'Year unknown';
 }
 
+// Path: germination
+class Translations$germination$en {
+	Translations$germination$en.internal(this._root);
+
+	final Translations _root; // ignore: unused_field
+
+	// Translations
+
+	/// en: 'Germination'
+	String get title => 'Germination';
+
+	/// en: 'Add test'
+	String get add => 'Add test';
+
+	/// en: 'Sample size'
+	String get sampleSize => 'Sample size';
+
+	/// en: 'Germinated'
+	String get germinated => 'Germinated';
+
+	/// en: 'No germination tests yet.'
+	String get none => 'No germination tests yet.';
+
+	/// en: '{percent}%'
+	String result({required Object percent}) => '${percent}%';
+}
+
 // Path: editVariety
 class Translations$editVariety$en {
 	Translations$editVariety$en.internal(this._root);
@@ -315,6 +343,12 @@ extension on Translations {
 			'detail.deleteConfirm' => 'Delete this seed?',
 			'detail.year' => ({required Object year}) => 'Year ${year}',
 			'detail.noYear' => 'Year unknown',
+			'germination.title' => 'Germination',
+			'germination.add' => 'Add test',
+			'germination.sampleSize' => 'Sample size',
+			'germination.germinated' => 'Germinated',
+			'germination.none' => 'No germination tests yet.',
+			'germination.result' => ({required Object percent}) => '${percent}%',
 			'editVariety.title' => 'Edit seed',
 			'editVariety.name' => 'Name',
 			'editVariety.category' => 'Category',

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

@@ -44,6 +44,7 @@ class TranslationsEs extends Translations with BaseTranslations<AppLocale, Trans
 	@override late final _Translations$inventory$es inventory = _Translations$inventory$es._(_root);
 	@override late final _Translations$quickAdd$es quickAdd = _Translations$quickAdd$es._(_root);
 	@override late final _Translations$detail$es detail = _Translations$detail$es._(_root);
+	@override late final _Translations$germination$es germination = _Translations$germination$es._(_root);
 	@override late final _Translations$editVariety$es editVariety = _Translations$editVariety$es._(_root);
 	@override late final _Translations$addLot$es addLot = _Translations$addLot$es._(_root);
 	@override late final _Translations$quantityKind$es quantityKind = _Translations$quantityKind$es._(_root);
@@ -120,6 +121,21 @@ class _Translations$detail$es extends Translations$detail$en {
 	@override String get noYear => 'Año desconocido';
 }
 
+// Path: germination
+class _Translations$germination$es extends Translations$germination$en {
+	_Translations$germination$es._(TranslationsEs root) : this._root = root, super.internal(root);
+
+	final TranslationsEs _root; // ignore: unused_field
+
+	// Translations
+	@override String get title => 'Germinación';
+	@override String get add => 'Añadir prueba';
+	@override String get sampleSize => 'Muestra';
+	@override String get germinated => 'Germinadas';
+	@override String get none => 'Aún no hay pruebas de germinación.';
+	@override String result({required Object percent}) => '${percent}%';
+}
+
 // Path: editVariety
 class _Translations$editVariety$es extends Translations$editVariety$en {
 	_Translations$editVariety$es._(TranslationsEs root) : this._root = root, super.internal(root);
@@ -208,6 +224,12 @@ extension on TranslationsEs {
 			'detail.deleteConfirm' => '¿Eliminar esta semilla?',
 			'detail.year' => ({required Object year}) => 'Año ${year}',
 			'detail.noYear' => 'Año desconocido',
+			'germination.title' => 'Germinación',
+			'germination.add' => 'Añadir prueba',
+			'germination.sampleSize' => 'Muestra',
+			'germination.germinated' => 'Germinadas',
+			'germination.none' => 'Aún no hay pruebas de germinación.',
+			'germination.result' => ({required Object percent}) => '${percent}%',
 			'editVariety.title' => 'Editar semilla',
 			'editVariety.name' => 'Nombre',
 			'editVariety.category' => 'Categoría',

apps/app_seeds/lib/state/variety_detail_cubit.dart

@@ -56,6 +56,18 @@ class VarietyDetailCubit extends Cubit<VarietyDetailState> {
   Future<void> linkSpecies(String speciesId) =>
       _repo.linkSpecies(varietyId, speciesId);
 
+  Future<void> addGerminationTest({
+    required String lotId,
+    int? testedOn,
+    int? sampleSize,
+    int? germinatedCount,
+  }) => _repo.addGerminationTest(
+    lotId: lotId,
+    testedOn: testedOn,
+    sampleSize: sampleSize,
+    germinatedCount: germinatedCount,
+  );
+
   Future<void> deleteVariety() async {
     await _repo.softDeleteVariety(varietyId);
     emit(

apps/app_seeds/lib/ui/variety_detail_screen.dart

@@ -139,6 +139,20 @@ class _DetailView extends StatelessWidget {
                 subtitle: lot.storageLocation == null
                     ? null
                     : Text(lot.storageLocation!),
+                trailing: Row(
+                  mainAxisSize: MainAxisSize.min,
+                  children: [
+                    if (lot.latestGerminationRate != null)
+                      _GerminationBadge(rate: lot.latestGerminationRate!),
+                    IconButton(
+                      key: Key('lot.germination.${lot.id}'),
+                      icon: const Icon(Icons.grass_outlined),
+                      tooltip: t.germination.title,
+                      onPressed: () =>
+                          _showGerminationSheet(context, cubit, lot),
+                    ),
+                  ],
+                ),
               ),
         ],
       ),
@@ -166,6 +180,135 @@ String _quantityLabel(Translations t, Quantity q) {
 String _trimDouble(double v) =>
     v == v.roundToDouble() ? v.toStringAsFixed(0) : v.toString();
 
+String _germinationPercent(Translations t, double rate) =>
+    t.germination.result(percent: (rate * 100).round());
+
+/// A compact pill showing the latest germination rate on a lot tile.
+class _GerminationBadge extends StatelessWidget {
+  const _GerminationBadge({required this.rate});
+
+  final double rate;
+
+  @override
+  Widget build(BuildContext context) {
+    final scheme = Theme.of(context).colorScheme;
+    return Container(
+      padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
+      decoration: BoxDecoration(
+        color: scheme.secondaryContainer,
+        borderRadius: BorderRadius.circular(12),
+      ),
+      child: Text(
+        _germinationPercent(context.t, rate),
+        style: TextStyle(
+          color: scheme.onSecondaryContainer,
+          fontWeight: FontWeight.w600,
+        ),
+      ),
+    );
+  }
+}
+
+Future<void> _showGerminationSheet(
+  BuildContext context,
+  VarietyDetailCubit cubit,
+  VarietyLot lot,
+) {
+  final t = context.t;
+  final sample = TextEditingController();
+  final germinated = TextEditingController();
+  return showModalBottomSheet<void>(
+    context: context,
+    isScrollControlled: true,
+    builder: (sheetContext) => Padding(
+      padding: EdgeInsets.only(
+        left: 16,
+        right: 16,
+        top: 16,
+        bottom: MediaQuery.of(sheetContext).viewInsets.bottom + 16,
+      ),
+      child: Column(
+        mainAxisSize: MainAxisSize.min,
+        crossAxisAlignment: CrossAxisAlignment.stretch,
+        children: [
+          Text(
+            t.germination.title,
+            style: Theme.of(sheetContext).textTheme.titleLarge,
+          ),
+          const SizedBox(height: 8),
+          if (lot.germinationTests.isEmpty)
+            Text(t.germination.none)
+          else
+            for (final test in lot.germinationTests)
+              ListTile(
+                dense: true,
+                contentPadding: EdgeInsets.zero,
+                leading: const Icon(Icons.grass_outlined),
+                title: Text(
+                  test.rate == null ? '—' : _germinationPercent(t, test.rate!),
+                ),
+                subtitle:
+                    (test.sampleSize != null && test.germinatedCount != null)
+                    ? Text('${test.germinatedCount}/${test.sampleSize}')
+                    : null,
+              ),
+          const Divider(),
+          Row(
+            children: [
+              Expanded(
+                child: TextField(
+                  key: const Key('germination.germinated'),
+                  controller: germinated,
+                  keyboardType: TextInputType.number,
+                  decoration: InputDecoration(
+                    labelText: t.germination.germinated,
+                    border: const OutlineInputBorder(),
+                  ),
+                ),
+              ),
+              const SizedBox(width: 12),
+              Expanded(
+                child: TextField(
+                  key: const Key('germination.sampleSize'),
+                  controller: sample,
+                  keyboardType: TextInputType.number,
+                  decoration: InputDecoration(
+                    labelText: t.germination.sampleSize,
+                    border: const OutlineInputBorder(),
+                  ),
+                ),
+              ),
+            ],
+          ),
+          const SizedBox(height: 16),
+          Row(
+            children: [
+              TextButton(
+                onPressed: () => Navigator.of(sheetContext).pop(),
+                child: Text(t.common.cancel),
+              ),
+              const Spacer(),
+              FilledButton(
+                key: const Key('germination.save'),
+                onPressed: () {
+                  cubit.addGerminationTest(
+                    lotId: lot.id,
+                    testedOn: DateTime.now().millisecondsSinceEpoch,
+                    sampleSize: int.tryParse(sample.text.trim()),
+                    germinatedCount: int.tryParse(germinated.text.trim()),
+                  );
+                  Navigator.of(sheetContext).pop();
+                },
+                child: Text(t.germination.add),
+              ),
+            ],
+          ),
+        ],
+      ),
+    ),
+  );
+}
+
 Future<void> _confirmDelete(
   BuildContext context,
   VarietyDetailCubit cubit,

apps/app_seeds/test/data/variety_detail_test.dart

@@ -97,4 +97,42 @@ void main() {
     final detail = await repo.watchVariety(id).first;
     expect(detail!.category, 'My tomatoes');
   });
+
+  test(
+    'addGerminationTest surfaces the latest derived rate on the lot',
+    () async {
+      final id = await repo.addQuickVariety(label: 'Maize');
+      final lotId = await repo.addLot(varietyId: id, harvestYear: 2024);
+      await repo.addGerminationTest(
+        lotId: lotId,
+        testedOn: 1000,
+        sampleSize: 20,
+        germinatedCount: 18,
+      );
+
+      final lot = (await repo.watchVariety(id).first)!.lots.single;
+      expect(lot.germinationTests, hasLength(1));
+      expect(lot.latestGerminationRate, closeTo(0.9, 1e-9));
+    },
+  );
+
+  test('watchVariety reacts to a germination test being added', () async {
+    final id = await repo.addQuickVariety(label: 'Maize');
+    final lotId = await repo.addLot(varietyId: id);
+    final queue = StreamQueue(repo.watchVariety(id));
+
+    final initial = await queue.next;
+    expect(initial!.lots.single.germinationTests, isEmpty);
+
+    await repo.addGerminationTest(
+      lotId: lotId,
+      sampleSize: 10,
+      germinatedCount: 9,
+    );
+
+    final updated = await queue.next;
+    expect(updated!.lots.single.latestGerminationRate, closeTo(0.9, 1e-9));
+
+    await queue.cancel();
+  });
 }

apps/app_seeds/test/ui/variety_detail_screen_test.dart

@@ -157,4 +157,42 @@ void main() {
       await disposeTree(tester);
     },
   );
+
+  testWidgets('recording a germination test shows the rate badge on the lot', (
+    tester,
+  ) async {
+    final repo = newTestRepository(db);
+    final id = await repo.addQuickVariety(label: 'Maize');
+    await repo.addLot(
+      varietyId: id,
+      harvestYear: 2024,
+      quantity: const Quantity(kind: QuantityKind.cob),
+    );
+
+    await tester.pumpWidget(
+      wrapDetail(
+        repository: repo,
+        varietyId: id,
+        species: newTestSpeciesRepository(db),
+      ),
+    );
+    await tester.pumpAndSettle();
+
+    await tester.tap(find.byIcon(Icons.grass_outlined).first);
+    await tester.pumpAndSettle();
+
+    await tester.enterText(
+      find.byKey(const Key('germination.germinated')),
+      '18',
+    );
+    await tester.enterText(
+      find.byKey(const Key('germination.sampleSize')),
+      '20',
+    );
+    await tester.tap(find.byKey(const Key('germination.save')));
+    await tester.pumpAndSettle();
+
+    expect(find.text('90%'), findsOneWidget); // germination badge on the lot
+    await disposeTree(tester);
+  });
 }