feat(inventory): month/year harvest date picker (schema v3)

Replace the free-text harvest year with a themed month/year picker:
a tappable field opens a green-styled dialog with month and year grids
(navigable, paginated years), month optional. Lots now read e.g.
"September 2021" or just "Year 2021".

- schema v3: add nullable Lot.harvest_month (1..12) + migration + tests
- repo/cubit propagate harvestMonth; localized month names (en/es) via slang

apps/app_seeds/lib/data/variety_repository.dart

@@ -65,6 +65,7 @@ class VarietyLot extends Equatable {
     required this.id,
     this.type = LotType.seed,
     this.harvestYear,
+    this.harvestMonth,
     this.quantity,
     this.storageLocation,
     this.germinationTests = const [],
@@ -73,6 +74,9 @@ class VarietyLot extends Equatable {
   final String id;
   final LotType type;
   final int? harvestYear;
+
+  /// Optional harvest month (1..12). Only meaningful when [harvestYear] is set.
+  final int? harvestMonth;
   final Quantity? quantity;
   final String? storageLocation;
   final List<GerminationEntry> germinationTests;
@@ -86,6 +90,7 @@ class VarietyLot extends Equatable {
     id,
     type,
     harvestYear,
+    harvestMonth,
     quantity,
     storageLocation,
     germinationTests,
@@ -110,7 +115,18 @@ class VernacularName extends Equatable {
   List<Object?> get props => [id, name, language, region];
 }
 
-/// The full detail of one variety (identity + its lots, names and first photo).
+/// One stored photo of a variety (encrypted BLOB in the DB).
+class VarietyPhoto extends Equatable {
+  const VarietyPhoto({required this.id, required this.bytes});
+
+  final String id;
+  final Uint8List bytes;
+
+  @override
+  List<Object?> get props => [id, bytes];
+}
+
+/// The full detail of one variety (identity + its lots, names and photos).
 class VarietyDetail extends Equatable {
   const VarietyDetail({
     required this.id,
@@ -121,7 +137,7 @@ class VarietyDetail extends Equatable {
     this.scientificName,
     this.lots = const [],
     this.vernacularNames = const [],
-    this.photo,
+    this.photos = const [],
   });
 
   final String id;
@@ -132,7 +148,7 @@ class VarietyDetail extends Equatable {
   final String? scientificName;
   final List<VarietyLot> lots;
   final List<VernacularName> vernacularNames;
-  final Uint8List? photo;
+  final List<VarietyPhoto> photos;
 
   @override
   List<Object?> get props => [
@@ -144,7 +160,7 @@ class VarietyDetail extends Equatable {
     scientificName,
     lots,
     vernacularNames,
-    photo,
+    photos,
   ];
 }
 
@@ -380,7 +396,7 @@ class VarietyRepository {
                     a.kind.equalsValue(AttachmentKind.photo) &
                     a.isDeleted.equals(false),
               )
-              ..limit(1))
+              ..orderBy([(a) => OrderingTerm(expression: a.createdAt)]))
             .get();
 
     return VarietyDetail(
@@ -401,7 +417,10 @@ class VarietyRepository {
             ),
           )
           .toList(),
-      photo: photos.isEmpty ? null : photos.first.bytes,
+      photos: [
+        for (final p in photos)
+          if (p.bytes != null) VarietyPhoto(id: p.id, bytes: p.bytes!),
+      ],
     );
   }
 
@@ -457,6 +476,7 @@ class VarietyRepository {
     required String varietyId,
     LotType type = LotType.seed,
     int? harvestYear,
+    int? harvestMonth,
     Quantity? quantity,
     String? storageLocation,
   }) async {
@@ -473,6 +493,7 @@ class VarietyRepository {
             lastAuthor: nodeId,
             type: Value(type),
             harvestYear: Value(harvestYear),
+            harvestMonth: Value(harvestMonth),
             quantityKind: Value(quantity?.kind.name),
             quantityPrecise: Value(quantity?.count?.toDouble()),
             quantityLabel: Value(quantity?.label),
@@ -482,12 +503,13 @@ class VarietyRepository {
     return id;
   }
 
-  /// Updates an existing lot's fields (LWW). The [quantity] and [harvestYear]
-  /// are set as given (null clears them).
+  /// Updates an existing lot's fields (LWW). The [quantity], [harvestYear] and
+  /// [harvestMonth] are set as given (null clears them).
   Future<void> updateLot({
     required String lotId,
     required LotType type,
     int? harvestYear,
+    int? harvestMonth,
     Quantity? quantity,
     String? storageLocation,
   }) async {
@@ -496,6 +518,7 @@ class VarietyRepository {
       LotsCompanion(
         type: Value(type),
         harvestYear: Value(harvestYear),
+        harvestMonth: Value(harvestMonth),
         quantityKind: Value(quantity?.kind.name),
         quantityPrecise: Value(quantity?.count?.toDouble()),
         quantityLabel: Value(quantity?.label),
@@ -558,6 +581,42 @@ class VarietyRepository {
     );
   }
 
+  /// Adds a photo (encrypted BLOB) to a variety. Returns the new attachment id.
+  Future<String> addPhoto(String varietyId, Uint8List bytes) async {
+    final (created, updated) = _stamp();
+    final id = idGen.newId();
+    await _db
+        .into(_db.attachments)
+        .insert(
+          AttachmentsCompanion.insert(
+            id: id,
+            createdAt: created,
+            updatedAt: updated,
+            lastAuthor: nodeId,
+            parentType: ParentType.variety,
+            parentId: varietyId,
+            kind: AttachmentKind.photo,
+            bytes: Value(bytes),
+            mimeType: const Value('image/jpeg'),
+          ),
+        );
+    return id;
+  }
+
+  /// Soft-deletes a photo (tombstone).
+  Future<void> removePhoto(String attachmentId) async {
+    final (_, updated) = _stamp();
+    await (_db.update(
+      _db.attachments,
+    )..where((a) => a.id.equals(attachmentId))).write(
+      AttachmentsCompanion(
+        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 {
@@ -608,6 +667,7 @@ class VarietyRepository {
       id: l.id,
       type: l.type,
       harvestYear: l.harvestYear,
+      harvestMonth: l.harvestMonth,
       storageLocation: l.storageLocation,
       germinationTests: germinationTests,
       quantity: hasQuantity