feat(inventory): local sharing — per-lot share terms, filter and printable catalog

The local half of the original Fase 2 (no network, no Offer entity yet):
- Lot sheet gains a 'do you share it?' choice (gift/swap first, sale last,
  never the default); declaring plenty of abundance reveals it with a nudge.
- Lot lines and list tiles badge shared batches; an 'I share' filter and
  a printable PDF catalog (paper bridge for fairs) round out the view.
- Catalog PDF embeds DejaVu (Latin-ext/Cyrillic/Greek); fonts are a
  per-locale resource like the OCR packs.

apps/app_seeds/lib/state/variety_detail_cubit.dart

@@ -80,6 +80,7 @@ class VarietyDetailCubit extends Cubit<VarietyDetailState> {
     String? originPlace,
     Abundance? abundance,
     PreservationFormat? preservationFormat,
+    OfferStatus offerStatus = OfferStatus.private,
   }) => _repo.addLot(
     varietyId: varietyId,
     type: type,
@@ -91,6 +92,7 @@ class VarietyDetailCubit extends Cubit<VarietyDetailState> {
     originPlace: originPlace,
     abundance: abundance,
     preservationFormat: preservationFormat,
+    offerStatus: offerStatus,
   );
 
   Future<void> updateLot({
@@ -104,6 +106,7 @@ class VarietyDetailCubit extends Cubit<VarietyDetailState> {
     String? originPlace,
     Abundance? abundance,
     PreservationFormat? preservationFormat,
+    OfferStatus offerStatus = OfferStatus.private,
   }) => _repo.updateLot(
     lotId: lotId,
     type: type,
@@ -115,6 +118,7 @@ class VarietyDetailCubit extends Cubit<VarietyDetailState> {
     originPlace: originPlace,
     abundance: abundance,
     preservationFormat: preservationFormat,
+    offerStatus: offerStatus,
   );
 
   Future<void> deleteLot(String lotId) => _repo.softDeleteLot(lotId);