feat(plantare): reproduction-commitment data layer (schema v9)

The Plantare — a promise to reproduce seed and return some (data-model §2.7,
the seed-domain Pledge with return_kind=similar). NOT a sale. Local-first
v1: your honest ledger of commitments (from/to a person by name); the
bilateral signed cross-party form is a later social-layer phase.

- New Plantares table (SyncColumns): varietyId, direction (iReturn/owedToMe),
  counterparty, owedDescription, madeOn, dueBy, status (open/returned/
  forgiven), settledOn, note. schemaVersion 8 -> 9 with a guarded createTable
  migration; schema exported + migration-test helper regenerated.
- VarietyRepository: createPlantare / watchPlantares / watchPlantaresForVariety
  / setPlantareStatus / deletePlantare (soft-delete, CRDT-stamped).
- Included in backups + sync: InventorySnapshot + JSON codec (round-trips
  isDeleted) + exportInventory/exportForSync/importInventory, so commitments
  survive restore and replicate LWW like every other row.

Tests: v1..v8 -> v9 migration + fresh v9; repo create/list/settle/reopen/
delete; and a backup round-trip preserving a commitment. 13 green.

UI (detail section + Plantares screen) follows.

apps/app_seeds/lib/data/export_import/inventory_json_codec.dart

@@ -208,6 +208,28 @@ class InventoryJsonCodec {
             'sortOrder': a.sortOrder,
           },
       ],
+      'plantares': [
+        for (final p in snapshot.plantares)
+          {
+            ..._syncMeta(
+              id: p.id,
+              createdAt: p.createdAt,
+              updatedAt: p.updatedAt,
+              lastAuthor: p.lastAuthor,
+              schemaRowVersion: p.schemaRowVersion,
+              isDeleted: p.isDeleted,
+            ),
+            'varietyId': p.varietyId,
+            'direction': p.direction.name,
+            'counterparty': p.counterparty,
+            'owedDescription': p.owedDescription,
+            'madeOn': p.madeOn,
+            'dueBy': p.dueBy,
+            'status': p.status.name,
+            'settledOn': p.settledOn,
+            'note': p.note,
+          },
+      ],
     });
   }
 
@@ -418,6 +440,28 @@ class InventoryJsonCodec {
           sortOrder: _int(m, 'sortOrder', fallback: 0),
         );
       }),
+      plantares: _rows(root, 'plantares', (m) {
+        return Plantare(
+          id: _string(m, 'id'),
+          createdAt: _int(m, 'createdAt'),
+          updatedAt: _string(m, 'updatedAt'),
+          lastAuthor: _string(m, 'lastAuthor'),
+          isDeleted: _bool(m, 'isDeleted'),
+          schemaRowVersion: _int(m, 'schemaRowVersion', fallback: 1),
+          varietyId: m['varietyId'] as String?,
+          direction:
+              _enumOr(PlantareDirection.values, m['direction'],
+                  PlantareDirection.iReturn),
+          counterparty: m['counterparty'] as String?,
+          owedDescription: m['owedDescription'] as String?,
+          madeOn: _int(m, 'madeOn'),
+          dueBy: m['dueBy'] as int?,
+          status:
+              _enumOr(PlantareStatus.values, m['status'], PlantareStatus.open),
+          settledOn: m['settledOn'] as int?,
+          note: m['note'] as String?,
+        );
+      }),
     );
   }
 

apps/app_seeds/lib/data/export_import/inventory_snapshot.dart

@@ -30,6 +30,7 @@ class InventorySnapshot {
     this.movements = const [],
     this.parties = const [],
     this.attachments = const [],
+    this.plantares = const [],
     this.speciesNamesById = const {},
   });
 
@@ -42,6 +43,7 @@ class InventorySnapshot {
   final List<Movement> movements;
   final List<Party> parties;
   final List<Attachment> attachments;
+  final List<Plantare> plantares;
 
   /// speciesId → scientificName, for the species referenced by [varieties].
   final Map<String, String> speciesNamesById;