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/variety_repository.dart

@@ -1707,6 +1707,80 @@ class VarietyRepository {
     return id;
   }
 
+  // --- Plantares: reproduction commitments (data-model §2.7) ----------------
+
+  /// Records a Plantare — a promise to reproduce seed and return some (or a
+  /// promise made TO you). Returns the new commitment id.
+  Future<String> createPlantare({
+    required PlantareDirection direction,
+    String? varietyId,
+    String? counterparty,
+    String? owedDescription,
+    int? dueBy,
+    String? note,
+  }) async {
+    final (created, updated) = await _stamp();
+    final id = idGen.newId();
+    await _db.into(_db.plantares).insert(
+          PlantaresCompanion.insert(
+            id: id,
+            createdAt: created,
+            updatedAt: updated,
+            lastAuthor: nodeId,
+            direction: direction,
+            varietyId: Value(varietyId),
+            counterparty: Value(counterparty),
+            owedDescription: Value(owedDescription),
+            madeOn: created,
+            dueBy: Value(dueBy),
+            note: Value(note),
+          ),
+        );
+    return id;
+  }
+
+  /// All live commitments, newest first (for the Plantares screen).
+  Stream<List<Plantare>> watchPlantares() => (_db.select(_db.plantares)
+        ..where((p) => p.isDeleted.equals(false))
+        ..orderBy([(p) => OrderingTerm.desc(p.madeOn)]))
+      .watch();
+
+  /// The commitments recorded against one variety.
+  Stream<List<Plantare>> watchPlantaresForVariety(String varietyId) =>
+      (_db.select(_db.plantares)
+            ..where(
+              (p) => p.varietyId.equals(varietyId) & p.isDeleted.equals(false),
+            )
+            ..orderBy([(p) => OrderingTerm.desc(p.madeOn)]))
+          .watch();
+
+  /// Moves a commitment to [status]; stamps the settle time for returned/
+  /// forgiven, clears it when reopened.
+  Future<void> setPlantareStatus(String id, PlantareStatus status) async {
+    final (now, updated) = await _stamp();
+    await (_db.update(_db.plantares)..where((p) => p.id.equals(id))).write(
+      PlantaresCompanion(
+        status: Value(status),
+        settledOn:
+            Value(status == PlantareStatus.open ? null : now),
+        updatedAt: Value(updated),
+        lastAuthor: Value(nodeId),
+      ),
+    );
+  }
+
+  /// Soft-deletes a commitment (tombstone, so it syncs as a removal).
+  Future<void> deletePlantare(String id) async {
+    final (_, updated) = await _stamp();
+    await (_db.update(_db.plantares)..where((p) => p.id.equals(id))).write(
+      PlantaresCompanion(
+        isDeleted: const Value(true),
+        updatedAt: Value(updated),
+        lastAuthor: Value(nodeId),
+      ),
+    );
+  }
+
   /// Snapshots the live inventory (tombstones excluded) for the interchange
   /// export — data-model §7. Includes photo bytes; the JSON codec embeds them
   /// as base64 and the CSV codec ignores them.
@@ -1742,6 +1816,9 @@ class VarietyRepository {
       attachments: await (_db.select(
         _db.attachments,
       )..where((a) => a.isDeleted.equals(false))).get(),
+      plantares: await (_db.select(
+        _db.plantares,
+      )..where((p) => p.isDeleted.equals(false))).get(),
     );
   }
 
@@ -1764,6 +1841,7 @@ class VarietyRepository {
       conditionChecks: await _db.select(_db.conditionChecks).get(),
       movements: await _db.select(_db.movements).get(),
       parties: await _db.select(_db.parties).get(),
+      plantares: await _db.select(_db.plantares).get(),
       // attachments intentionally omitted — photos don't ride the sync wire.
     );
   }
@@ -1856,6 +1934,14 @@ class VarietyRepository {
         updatedAtOf: (r) => r.updatedAt,
         reconciler: reconciler,
       );
+      summary += await _importMutableRows(
+        table: _db.plantares,
+        idColumn: _db.plantares.id,
+        rows: snapshot.plantares,
+        idOf: (r) => r.id,
+        updatedAtOf: (r) => r.updatedAt,
+        reconciler: reconciler,
+      );
       summary += await _importMovements(snapshot.movements, reconciler);
     });
 
@@ -1868,6 +1954,7 @@ class VarietyRepository {
       for (final c in snapshot.conditionChecks) c.updatedAt,
       for (final p in snapshot.parties) p.updatedAt,
       for (final a in snapshot.attachments) a.updatedAt,
+      for (final pl in snapshot.plantares) pl.updatedAt,
     ]);
     if (maxIncoming != null) {
       _clock = _clock.receiveEvent(maxIncoming, _now());