feat(plantare): usable UI — commitments screen, add sheet, entry points

The reproduction-commitment (Plantare) UI, local-first and plain-spoken:
- A Plantares screen (drawer entry, /plantares) listing your commitments,
  grouped Open / Done, with a big 'mark returned', a menu (let it go / reopen
  / remove) and an empty-state that explains what a Plantare is.
- An add sheet (scrollable): a two-choice 'who reproduces & returns' (I return
  / owed to me), an optional 'with whom', an optional 'what comes back' in the
  grower's own words, and a note. No sale, no currency — a promise.
- Reachable from a seed too: an 'Add a commitment' action on the variety
  detail, pre-attached to that variety.
- i18n en/es/pt/ast (human words: 'Plantare' + a plain explanation).

Added the Plantares screen to the small-phone overflow guard (18 cases green).

apps/app_seeds/lib/ui/plantare_sheet.dart

@@ -0,0 +1,145 @@
+import 'package:flutter/material.dart';
+
+import '../data/variety_repository.dart';
+import '../db/enums.dart';
+import '../i18n/strings.g.dart';
+import 'theme.dart';
+
+/// Opens the "add a Plantare" sheet — a reproduction commitment. Optionally
+/// pre-attached to [varietyId] (when opened from a variety's detail).
+Future<void> showPlantareSheet(
+  BuildContext context, {
+  required VarietyRepository repository,
+  String? varietyId,
+}) {
+  return showModalBottomSheet<void>(
+    context: context,
+    isScrollControlled: true,
+    builder: (_) => _PlantareSheet(repository: repository, varietyId: varietyId),
+  );
+}
+
+class _PlantareSheet extends StatefulWidget {
+  const _PlantareSheet({required this.repository, this.varietyId});
+
+  final VarietyRepository repository;
+  final String? varietyId;
+
+  @override
+  State<_PlantareSheet> createState() => _PlantareSheetState();
+}
+
+class _PlantareSheetState extends State<_PlantareSheet> {
+  PlantareDirection _direction = PlantareDirection.iReturn;
+  final _counterparty = TextEditingController();
+  final _owed = TextEditingController();
+  final _note = TextEditingController();
+  bool _saving = false;
+
+  @override
+  void dispose() {
+    _counterparty.dispose();
+    _owed.dispose();
+    _note.dispose();
+    super.dispose();
+  }
+
+  String? _nullIfBlank(String s) => s.trim().isEmpty ? null : s.trim();
+
+  Future<void> _save() async {
+    setState(() => _saving = true);
+    await widget.repository.createPlantare(
+      direction: _direction,
+      varietyId: widget.varietyId,
+      counterparty: _nullIfBlank(_counterparty.text),
+      owedDescription: _nullIfBlank(_owed.text),
+      note: _nullIfBlank(_note.text),
+    );
+    if (mounted) Navigator.of(context).pop();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final t = context.t;
+    return Padding(
+      padding: EdgeInsets.only(
+        left: 16,
+        right: 16,
+        top: 16,
+        bottom: MediaQuery.of(context).viewInsets.bottom + 16,
+      ),
+      child: SingleChildScrollView(
+        child: Column(
+          mainAxisSize: MainAxisSize.min,
+          crossAxisAlignment: CrossAxisAlignment.stretch,
+          children: [
+            Text(t.plantare.add,
+                style: Theme.of(context).textTheme.titleLarge),
+            const SizedBox(height: 4),
+            Text(t.plantare.help,
+                style: const TextStyle(color: seedMuted, fontSize: 13)),
+            const SizedBox(height: 16),
+            Text(t.plantare.direction,
+                style: Theme.of(context).textTheme.labelLarge),
+            const SizedBox(height: 6),
+            // Two big, human choices — no jargon.
+            for (final d in PlantareDirection.values)
+              ListTile(
+                key: Key('plantare.direction.${d.name}'),
+                contentPadding: EdgeInsets.zero,
+                leading: Icon(
+                  _direction == d
+                      ? Icons.radio_button_checked
+                      : Icons.radio_button_unchecked,
+                  color: _direction == d ? seedGreen : seedMuted,
+                ),
+                title: Text(d == PlantareDirection.iReturn
+                    ? t.plantare.iReturn
+                    : t.plantare.owedToMe),
+                onTap: () => setState(() => _direction = d),
+              ),
+            const SizedBox(height: 8),
+            TextField(
+              key: const Key('plantare.counterparty'),
+              controller: _counterparty,
+              textCapitalization: TextCapitalization.words,
+              decoration: InputDecoration(
+                labelText: t.plantare.counterparty,
+                helperText: t.plantare.counterpartyHint,
+                border: const OutlineInputBorder(),
+              ),
+            ),
+            const SizedBox(height: 12),
+            TextField(
+              key: const Key('plantare.owed'),
+              controller: _owed,
+              decoration: InputDecoration(
+                labelText: t.plantare.owed,
+                helperText: t.plantare.owedHint,
+                helperMaxLines: 2,
+                border: const OutlineInputBorder(),
+              ),
+            ),
+            const SizedBox(height: 12),
+            TextField(
+              key: const Key('plantare.note'),
+              controller: _note,
+              minLines: 1,
+              maxLines: 3,
+              decoration: InputDecoration(
+                labelText: t.plantare.note,
+                border: const OutlineInputBorder(),
+              ),
+            ),
+            const SizedBox(height: 20),
+            FilledButton(
+              key: const Key('plantare.save'),
+              onPressed: _saving ? null : _save,
+              child: Text(t.plantare.save),
+            ),
+          ],
+        ),
+      ),
+    );
+  }
+}