feat(plantare): surface product link + dates; spec the bilateral record

The Plantaré screen stored madeOn/dueBy/varietyId but showed none of them,
so it felt half-built. Surface what's already there (no schema change):

- watchPlantareViews() joins each commitment with its variety label
- tile shows the made-on date, a "Return by {date}" line (amber + "overdue"
  when an open promise is past due, via new seedWarning colour), the variety
  name, and taps through to /variety/:id
- add sheet gains an optional return-by date picker (createPlantare already
  took dueBy)
- variety detail shows a read-only commitments section (hidden when empty,
  no add button — honours the single hand-over door)
- i18n en/es/pt/ast; tests for the join, dueBy round-trip, tile, and section

Also specs the deferred two-sided record in docs/design/plantare-bilateral.md
(Nostr pubkey counterparty, PlantareTransport propose->accept->counter-sign,
deferred key/signature/movement columns, provenance DAG, reputation anchor),
with a faithful transcription of the paper Plantaré v0.4 (BAH-Semillero 2009,
CC-BY-SA). Cross-linked from data-model §2.7 and sharing-model §6.

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

@@ -1779,6 +1779,27 @@ class Translations$plantare$en {
 
 	/// en: 'Remove this commitment?'
 	String get removeConfirm => 'Remove this commitment?';
+
+	/// en: 'Return by {date}'
+	String returnBy({required Object date}) => 'Return by ${date}';
+
+	/// en: 'overdue'
+	String get overdue => 'overdue';
+
+	/// en: 'Return by (optional)'
+	String get dueByLabel => 'Return by (optional)';
+
+	/// en: 'A gentle reminder, never enforced'
+	String get dueByHint => 'A gentle reminder, never enforced';
+
+	/// en: 'Pick a date'
+	String get pickDate => 'Pick a date';
+
+	/// en: 'Clear date'
+	String get clearDate => 'Clear date';
+
+	/// en: 'Commitments'
+	String get sectionTitle => 'Commitments';
 }
 
 // Path: handover
@@ -2980,6 +3001,13 @@ extension on Translations {
 			'plantare.openSection' => 'Open',
 			'plantare.settledSection' => 'Done',
 			'plantare.removeConfirm' => 'Remove this commitment?',
+			'plantare.returnBy' => ({required Object date}) => 'Return by ${date}',
+			'plantare.overdue' => 'overdue',
+			'plantare.dueByLabel' => 'Return by (optional)',
+			'plantare.dueByHint' => 'A gentle reminder, never enforced',
+			'plantare.pickDate' => 'Pick a date',
+			'plantare.clearDate' => 'Clear date',
+			'plantare.sectionTitle' => 'Commitments',
 			'handover.title' => 'Seeds changed hands',
 			'handover.help' => 'A gift, a swap or a sale — note it down, with a return promise or without.',
 			'handover.iGave' => 'I gave seeds',
@@ -2998,6 +3026,8 @@ extension on Translations {
 			'sale.iSold' => 'I sold',
 			'sale.iBought' => 'I bought',
 			'sale.direction' => 'Sold or bought?',
+			_ => null,
+		} ?? switch (path) {
 			'sale.counterparty' => 'With whom?',
 			'sale.counterpartyHint' => 'A person or a collective (optional)',
 			'sale.amount' => 'Amount',
@@ -3005,8 +3035,6 @@ extension on Translations {
 			'sale.currencyHint' => '€, Ğ1, hours… (optional)',
 			'sale.hours' => 'hours',
 			'sale.note' => 'Note (optional)',
-			_ => null,
-		} ?? switch (path) {
 			'sale.save' => 'Save',
 			'sale.delete' => 'Remove',
 			'sale.removeConfirm' => 'Remove this sale?',