feat(ux): usable amounts, colour-coded category/form chips, currency quick-picks

Four usability passes across the everyday flows:

- Quantity picker: a countable unit (cob/pod/ear…) now defaults to 1 and
  the stepper clamps at a minimum of 1 — you can never store 'a cob' with
  a blank/zero figure. Vibe units (a few) still carry no number.
- Category & form chips are colour-coded (new category_palette.dart): a
  small muted earthy palette maps each botanical family to a STABLE
  tonality (fill + readable ink), and each lot form gets its own tone.
  Applied to the inventory filter bar (now grouped attributes | forms |
  families, separated by a hairline), the list's category headers (a
  matching colour dot), and the lot-form selector.
- Sale currency: quick-pick chips (€ · Ğ1 · hours) fill the field in one
  tap — Ğ1 offered quietly among familiar options, never imposed — while
  free text still takes anything else. New i18n key sale.hours (en/es/pt/ast).

Tests: quantity_picker_test (default-1, clamp, vibe, clear-still-1),
category_palette_test (stable/distinct swatches); overflow guard + the
inventory widget tests stay green.

apps/app_seeds/lib/i18n/ast.i18n.json

@@ -592,6 +592,7 @@
     "amount": "Importe",
     "currency": "Moneda",
     "currencyHint": "€, Ğ1, hores… (opcional)",
+    "hours": "hores",
     "note": "Nota (opcional)",
     "save": "Guardar",
     "delete": "Quitar",

apps/app_seeds/lib/i18n/en.i18n.json

@@ -595,6 +595,7 @@
     "amount": "Amount",
     "currency": "Currency",
     "currencyHint": "€, Ğ1, hours… (optional)",
+    "hours": "hours",
     "note": "Note (optional)",
     "save": "Save",
     "delete": "Remove",

apps/app_seeds/lib/i18n/es.i18n.json

@@ -594,6 +594,7 @@
     "amount": "Importe",
     "currency": "Moneda",
     "currencyHint": "€, Ğ1, horas… (opcional)",
+    "hours": "horas",
     "note": "Nota (opcional)",
     "save": "Guardar",
     "delete": "Quitar",

apps/app_seeds/lib/i18n/pt.i18n.json

@@ -591,6 +591,7 @@
     "amount": "Montante",
     "currency": "Moeda",
     "currencyHint": "€, Ğ1, horas… (opcional)",
+    "hours": "horas",
     "note": "Nota (opcional)",
     "save": "Guardar",
     "delete": "Remover",

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

@@ -4,9 +4,9 @@
 /// To regenerate, run: `dart run slang`
 ///
 /// Locales: 4
-/// Strings: 1828 (457 per locale)
+/// Strings: 1832 (458 per locale)
 ///
-/// Built on 2026-07-11 at 00:20 UTC
+/// Built on 2026-07-11 at 04:03 UTC
 
 // coverage:ignore-file
 // ignore_for_file: type=lint, unused_import

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

@@ -860,6 +860,7 @@ class _Translations$sale$ast extends Translations$sale$en {
 	@override String get amount => 'Importe';
 	@override String get currency => 'Moneda';
 	@override String get currencyHint => '€, Ğ1, hores… (opcional)';
+	@override String get hours => 'hores';
 	@override String get note => 'Nota (opcional)';
 	@override String get save => 'Guardar';
 	@override String get delete => 'Quitar';
@@ -1659,6 +1660,7 @@ extension on TranslationsAst {
 			'sale.amount' => 'Importe',
 			'sale.currency' => 'Moneda',
 			'sale.currencyHint' => '€, Ğ1, hores… (opcional)',
+			'sale.hours' => 'hores',
 			'sale.note' => 'Nota (opcional)',
 			'sale.save' => 'Guardar',
 			'sale.delete' => 'Quitar',

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

@@ -1638,6 +1638,9 @@ class Translations$sale$en {
 	/// en: '€, Ğ1, hours… (optional)'
 	String get currencyHint => '€, Ğ1, hours… (optional)';
 
+	/// en: 'hours'
+	String get hours => 'hours';
+
 	/// en: 'Note (optional)'
 	String get note => 'Note (optional)';
 
@@ -2563,6 +2566,7 @@ extension on Translations {
 			'sale.amount' => 'Amount',
 			'sale.currency' => 'Currency',
 			'sale.currencyHint' => '€, Ğ1, hours… (optional)',
+			'sale.hours' => 'hours',
 			'sale.note' => 'Note (optional)',
 			'sale.save' => 'Save',
 			'sale.delete' => 'Remove',

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

@@ -862,6 +862,7 @@ class _Translations$sale$es extends Translations$sale$en {
 	@override String get amount => 'Importe';
 	@override String get currency => 'Moneda';
 	@override String get currencyHint => '€, Ğ1, horas… (opcional)';
+	@override String get hours => 'horas';
 	@override String get note => 'Nota (opcional)';
 	@override String get save => 'Guardar';
 	@override String get delete => 'Quitar';
@@ -1663,6 +1664,7 @@ extension on TranslationsEs {
 			'sale.amount' => 'Importe',
 			'sale.currency' => 'Moneda',
 			'sale.currencyHint' => '€, Ğ1, horas… (opcional)',
+			'sale.hours' => 'horas',
 			'sale.note' => 'Nota (opcional)',
 			'sale.save' => 'Guardar',
 			'sale.delete' => 'Quitar',

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

@@ -859,6 +859,7 @@ class _Translations$sale$pt extends Translations$sale$en {
 	@override String get amount => 'Montante';
 	@override String get currency => 'Moeda';
 	@override String get currencyHint => '€, Ğ1, horas… (opcional)';
+	@override String get hours => 'horas';
 	@override String get note => 'Nota (opcional)';
 	@override String get save => 'Guardar';
 	@override String get delete => 'Remover';
@@ -1657,6 +1658,7 @@ extension on TranslationsPt {
 			'sale.amount' => 'Montante',
 			'sale.currency' => 'Moeda',
 			'sale.currencyHint' => '€, Ğ1, horas… (opcional)',
+			'sale.hours' => 'horas',
 			'sale.note' => 'Nota (opcional)',
 			'sale.save' => 'Guardar',
 			'sale.delete' => 'Remover',

apps/app_seeds/lib/ui/category_palette.dart

@@ -0,0 +1,56 @@
+import 'package:flutter/material.dart';
+
+import '../db/enums.dart';
+import 'theme.dart';
+
+/// A colour for a chip/label: a soft [fill] to tint the background and a darker,
+/// same-hue [ink] readable on that fill and on white (text, dot, checkmark).
+class Swatch {
+  const Swatch(this.fill, this.ink);
+  final Color fill;
+  final Color ink;
+}
+
+/// A small, muted, earthy palette — one low-saturation key, different hues — so
+/// botanical families (categories) are distinguishable at a glance without
+/// shouting over the green brand. Kept calm on purpose (soft fills, legible
+/// ink). Order is stable; new entries append only.
+const _familyPalette = <Swatch>[
+  Swatch(Color(0xFFE8EEDA), Color(0xFF556B2F)), // olive
+  Swatch(Color(0xFFF3E2D8), Color(0xFF9C5B3B)), // terracotta
+  Swatch(Color(0xFFF3EBD3), Color(0xFF8A6D1E)), // ochre
+  Swatch(Color(0xFFDDEAE6), Color(0xFF3E7168)), // sage teal
+  Swatch(Color(0xFFF0E1E4), Color(0xFF9B5566)), // dusty rose
+  Swatch(Color(0xFFE0E6EE), Color(0xFF4A6489)), // slate blue
+  Swatch(Color(0xFFE9E1EE), Color(0xFF6E5090)), // plum
+  Swatch(Color(0xFFEBE3D8), Color(0xFF7A5A3A)), // warm brown
+];
+
+/// A stable (launch-to-launch, platform-independent) hash of a category name.
+/// `String.hashCode` is randomised per run, which would reshuffle colours on
+/// every launch — so fold the code units ourselves (FNV-1a-ish).
+int _stableHash(String s) {
+  var h = 0x811c9dc5;
+  for (final c in s.codeUnits) {
+    h = (h ^ c) * 0x01000193;
+    h &= 0xffffffff;
+  }
+  return h;
+}
+
+/// The stable colour for a free-text category (a botanical family). The same
+/// name always maps to the same tonality.
+Swatch categorySwatch(String category) =>
+    _familyPalette[_stableHash(category) % _familyPalette.length];
+
+/// A fixed tonality per lot form, so the form chips read as their own colour
+/// group (distinct from the family chips). Greens for the leafy forms, warmer
+/// tones for woody/underground ones.
+Swatch lotTypeSwatch(LotType type) => switch (type) {
+  LotType.seed => const Swatch(seedPrimaryContainer, seedOnPrimaryContainer),
+  LotType.seedling => const Swatch(Color(0xFFDDEBCF), Color(0xFF4E7A2E)),
+  LotType.plant => const Swatch(Color(0xFFD9EAD9), Color(0xFF2F7D34)),
+  LotType.tree => const Swatch(Color(0xFFE3D9C8), Color(0xFF6B4F2A)),
+  LotType.bulb => const Swatch(Color(0xFFF3E9CF), Color(0xFF8A6D1E)),
+  LotType.cutting => const Swatch(Color(0xFFE6EAD3), Color(0xFF63702F)),
+};

apps/app_seeds/lib/ui/inventory_list_screen.dart

@@ -9,6 +9,7 @@ import '../domain/seed_viability.dart';
 import '../i18n/strings.g.dart';
 import '../services/share_catalog_service.dart';
 import '../state/inventory_cubit.dart';
+import 'category_palette.dart';
 import 'draft_triage.dart';
 import 'label_print_sheet.dart';
 import 'quantity_kind_l10n.dart';
@@ -293,7 +294,10 @@ class _FilterBar extends StatelessWidget {
       return const SizedBox.shrink();
     }
 
-    final chips = <Widget>[
+    // Filters read as three colour-coded groups, separated by a thin rule:
+    // attributes (green icons) · forms (per-form tonality) · families (each a
+    // stable earthy tonality). Grouping + colour makes a long row scannable.
+    final attrChips = <Widget>[
       if (hasShared)
         FilterChip(
           key: const Key('inventory.filter.sharing'),
@@ -330,19 +334,26 @@ class _FilterBar extends StatelessWidget {
           selected: state.needsReproductionOnly,
           onSelected: (_) => cubit.toggleNeedsReproductionOnly(),
         ),
-      for (final category in categories)
+    ];
-        FilterChip(
+    final formChips = <Widget>[
-          key: Key('inventory.filter.category.$category'),
-          label: Text(category),
-          selected: state.categoryFilter.contains(category),
-          onSelected: (_) => cubit.toggleCategory(category),
-        ),
       for (final form in forms)
-        FilterChip(
+        _SwatchFilterChip(
           key: Key('inventory.filter.type.${form.name}'),
-          label: Text(lotTypeLabel(t, form)),
+          swatch: lotTypeSwatch(form),
+          label: lotTypeLabel(t, form),
+          icon: iconForLotType(form),
           selected: state.typeFilter.contains(form),
-          onSelected: (_) => cubit.toggleType(form),
+          onSelected: () => cubit.toggleType(form),
+        ),
+    ];
+    final categoryChips = <Widget>[
+      for (final category in categories)
+        _SwatchFilterChip(
+          key: Key('inventory.filter.category.$category'),
+          swatch: categorySwatch(category),
+          label: category,
+          selected: state.categoryFilter.contains(category),
+          onSelected: () => cubit.toggleCategory(category),
         ),
     ];
     final hasActiveFilter =
@@ -352,25 +363,80 @@ class _FilterBar extends StatelessWidget {
         state.needsReproductionOnly ||
         state.sharingOnly;
 
-    return SingleChildScrollView(
+    // Lay out the groups in order, dropping a hairline divider between any two
-      scrollDirection: Axis.horizontal,
+    // that both have chips.
-      padding: const EdgeInsets.symmetric(horizontal: 12),
+    final groups = [attrChips, formChips, categoryChips].where((g) => g.isNotEmpty);
-      child: Row(
+    final row = <Widget>[];
-        children: [
+    for (final group in groups) {
-          for (final chip in chips)
+      if (row.isNotEmpty) row.add(const _FilterGroupDivider());
-            Padding(
+      for (final chip in group) {
+        row.add(Padding(
           padding: const EdgeInsetsDirectional.only(end: 8),
           child: chip,
-            ),
+        ));
-          if (hasActiveFilter)
+      }
-            TextButton.icon(
+    }
+    if (hasActiveFilter) {
+      row.add(TextButton.icon(
         key: const Key('inventory.filter.clear'),
         onPressed: cubit.clearFilters,
         icon: const Icon(Icons.clear, size: 18),
         label: Text(t.inventory.clearFilters),
-            ),
+      ));
-        ],
+    }
-      ),
+
+    return SingleChildScrollView(
+      scrollDirection: Axis.horizontal,
+      padding: const EdgeInsets.symmetric(horizontal: 12),
+      child: Row(children: row),
+    );
+  }
+}
+
+/// A thin vertical rule separating filter groups in the horizontal chip row.
+class _FilterGroupDivider extends StatelessWidget {
+  const _FilterGroupDivider();
+
+  @override
+  Widget build(BuildContext context) => Container(
+        width: 1,
+        height: 22,
+        margin: const EdgeInsetsDirectional.only(end: 8),
+        color: seedOutline,
+      );
+}
+
+/// A [FilterChip] tinted with a [Swatch]: a soft fill when idle, a stronger
+/// same-hue fill when selected, with matching ink for the label, border,
+/// checkmark and optional leading [icon].
+class _SwatchFilterChip extends StatelessWidget {
+  const _SwatchFilterChip({
+    required this.swatch,
+    required this.label,
+    required this.selected,
+    required this.onSelected,
+    this.icon,
+    super.key,
+  });
+
+  final Swatch swatch;
+  final String label;
+  final bool selected;
+  final VoidCallback onSelected;
+  final IconData? icon;
+
+  @override
+  Widget build(BuildContext context) {
+    return FilterChip(
+      label: Text(label),
+      avatar: icon == null ? null : Icon(icon, size: 18, color: swatch.ink),
+      selected: selected,
+      onSelected: (_) => onSelected(),
+      backgroundColor: swatch.fill,
+      selectedColor: swatch.ink.withValues(alpha: 0.24),
+      checkmarkColor: swatch.ink,
+      side: BorderSide(color: swatch.ink.withValues(alpha: 0.35)),
+      labelStyle: TextStyle(color: swatch.ink, fontWeight: FontWeight.w500),
     );
   }
 }
@@ -451,16 +517,31 @@ class _CategoryHeader extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    // Same tonality as this family's filter chip, so header and chip read as a
+    // pair. The uncategorised bucket keeps the plain green.
+    final swatch = categorySwatch(title);
     return Padding(
       padding: const EdgeInsets.fromLTRB(16, 18, 16, 6),
+      child: Row(
+        children: [
+          Container(
+            width: 10,
+            height: 10,
+            margin: const EdgeInsetsDirectional.only(end: 8),
+            decoration: BoxDecoration(color: swatch.ink, shape: BoxShape.circle),
+          ),
+          Flexible(
             // Base on the text theme so it honours the system font-scale factor.
             child: Text(
               title,
               style: Theme.of(context).textTheme.titleMedium?.copyWith(
-          fontWeight: FontWeight.w500,
+                fontWeight: FontWeight.w600,
-          color: seedGreen,
+                color: swatch.ink,
               ),
             ),
+          ),
+        ],
+      ),
     );
   }
 }

apps/app_seeds/lib/ui/quantity_picker.dart

@@ -3,6 +3,7 @@ import 'package:flutter/material.dart';
 
 import '../db/enums.dart';
 import '../i18n/strings.g.dart';
+import 'category_palette.dart';
 import 'quantity_kind_l10n.dart';
 import 'seed_glyph.dart';
 import 'theme.dart';
@@ -76,16 +77,26 @@ class LotTypeSelector extends StatelessWidget {
       runSpacing: 8,
       children: [
         for (final type in LotType.values)
-          ChoiceChip(
+          _buildTypeChip(t, type),
+      ],
+    );
+  }
+
+  Widget _buildTypeChip(Translations t, LotType type) {
+    final swatch = lotTypeSwatch(type);
+    final selected = value == type;
+    return ChoiceChip(
       key: Key('lotType.${type.name}'),
-            selected: value == type,
+      selected: selected,
       onSelected: (_) => onChanged(type),
       avatar: type == LotType.seed
           ? const SeedGlyph(SeedGlyphs.jars, size: 18)
-                : Icon(iconForLotType(type), size: 18),
+          : Icon(iconForLotType(type), size: 18, color: swatch.ink),
       label: Text(lotTypeLabel(t, type)),
-          ),
+      backgroundColor: swatch.fill,
-      ],
+      selectedColor: swatch.ink.withValues(alpha: 0.24),
+      side: BorderSide(color: swatch.ink.withValues(alpha: 0.35)),
+      labelStyle: TextStyle(color: swatch.ink, fontWeight: FontWeight.w500),
     );
   }
 }
@@ -189,19 +200,29 @@ class _QuantityPickerState extends State<QuantityPicker> {
       widget.onChanged(null);
       return;
     }
-    final n = num.tryParse(_countController.text.trim().replaceAll(',', '.'));
+    // A countable unit always carries a number ≥ 1 — "3 cobs", never an empty
-    widget.onChanged(Quantity(kind: kind, count: kind.countable ? n : null));
+    // "cob". Blank/zero/garbage while typing falls back to 1, so you can never
+    // save a countable amount with no figure.
+    final parsed = num.tryParse(_countController.text.trim().replaceAll(',', '.'));
+    final count = kind.countable ? ((parsed == null || parsed < 1) ? 1 : parsed) : null;
+    widget.onChanged(Quantity(kind: kind, count: count));
   }
 
   void _select(QuantityKind kind) {
-    setState(() => _kind = kind);
+    setState(() {
+      _kind = kind;
+      // Selecting a countable unit with no number yet defaults it to 1.
+      if (kind.countable && (num.tryParse(_countController.text.trim()) == null)) {
+        _countController.text = '1';
+      }
+    });
     _emit();
   }
 
   void _bump(int delta) {
-    final current = int.tryParse(_countController.text.trim()) ?? 0;
+    final current = int.tryParse(_countController.text.trim()) ?? 1;
-    final next = (current + delta).clamp(0, 9999);
+    final next = (current + delta).clamp(1, 9999);
-    _countController.text = next == 0 ? '' : '$next';
+    _countController.text = '$next';
     _emit();
   }
 
@@ -219,6 +240,7 @@ class _QuantityPickerState extends State<QuantityPicker> {
           children: [
             for (final kind in kinds)
               _ScaleItem(
+                key: Key('quantity.kind.${kind.name}'),
                 kind: kind,
                 label: unitLabel(t, kind),
                 selected: _kind == kind,
@@ -273,6 +295,7 @@ class _ScaleItem extends StatelessWidget {
     required this.label,
     required this.selected,
     required this.onTap,
+    super.key,
   });
 
   final QuantityKind kind;

apps/app_seeds/lib/ui/sale_sheet.dart

@@ -132,14 +132,31 @@ class _SaleSheetState extends State<_SaleSheet> {
                     controller: _currency,
                     decoration: InputDecoration(
                       labelText: t.sale.currency,
-                      helperText: t.sale.currencyHint,
-                      helperMaxLines: 2,
                       border: const OutlineInputBorder(),
                     ),
+                    onChanged: (_) => setState(() {}),
                   ),
                 ),
               ],
             ),
+            const SizedBox(height: 8),
+            // Quick picks so a currency is one tap. Ğ1 sits quietly among the
+            // familiar ones — offered, never imposed — and free text still takes
+            // anything else.
+            Wrap(
+              spacing: 8,
+              children: [
+                for (final c in ['€', 'Ğ1', t.sale.hours])
+                  ChoiceChip(
+                    key: Key('sale.currencyChip.$c'),
+                    label: Text(c),
+                    selected: _currency.text.trim() == c,
+                    onSelected: (sel) => setState(() {
+                      _currency.text = sel ? c : '';
+                    }),
+                  ),
+              ],
+            ),
             const SizedBox(height: 12),
             TextField(
               key: const Key('sale.note'),

apps/app_seeds/test/ui/category_palette_test.dart

@@ -0,0 +1,37 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:tane/db/enums.dart';
+import 'package:tane/ui/category_palette.dart';
+
+/// Category/form colours must be STABLE (same name → same tonality every
+/// launch) so a family's chip and list header always match.
+void main() {
+  test('a category always maps to the same swatch', () {
+    final a = categorySwatch('Solanáceas');
+    final b = categorySwatch('Solanáceas');
+    expect(a.fill, b.fill);
+    expect(a.ink, b.ink);
+  });
+
+  test('different families generally get different tonalities', () {
+    final names = [
+      'Solanáceas',
+      'Leguminosas',
+      'Cucurbitáceas',
+      'Brasicáceas',
+      'Asteráceas',
+      'Amarantáceas',
+    ];
+    final inks = {for (final n in names) categorySwatch(n).ink};
+    // Not required to be all-distinct (palette wraps), but a fixed input set
+    // must not collapse to a single colour.
+    expect(inks.length, greaterThan(1));
+  });
+
+  test('every lot form has its own swatch', () {
+    for (final type in LotType.values) {
+      final s = lotTypeSwatch(type);
+      expect(s.fill, isNotNull);
+      expect(s.ink, isNotNull);
+    }
+  });
+}

apps/app_seeds/test/ui/quantity_picker_test.dart

@@ -0,0 +1,83 @@
+import 'package:commons_core/commons_core.dart';
+import 'package:flutter/material.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:tane/db/enums.dart';
+import 'package:tane/ui/quantity_picker.dart';
+
+import '../support/test_support.dart';
+
+/// A countable amount must never be blank: picking cob/pod/… defaults to 1 and
+/// the stepper can't drop below 1 — you can't save "a cob" with no figure.
+void main() {
+  Quantity? emitted;
+
+  Future<void> pumpPicker(WidgetTester tester,
+      {LotType type = LotType.seed}) async {
+    emitted = null;
+    final db = newTestDatabase();
+    addTearDown(db.close);
+    await tester.pumpWidget(wrapScreen(
+      repository: newTestRepository(db),
+      child: Scaffold(
+        body: QuantityPicker(
+          type: type,
+          onChanged: (q) => emitted = q,
+        ),
+      ),
+    ));
+    await tester.pump();
+  }
+
+  testWidgets('selecting a countable unit defaults the count to 1',
+      (tester) async {
+    await pumpPicker(tester);
+    await tester.tap(find.byKey(const Key('quantity.kind.cob')));
+    await tester.pump();
+
+    expect(emitted, isNotNull);
+    expect(emitted!.kind, QuantityKind.cob);
+    expect(emitted!.count, 1);
+    expect(
+      find.widgetWithText(TextField, '1'),
+      findsOneWidget,
+      reason: 'the count field shows 1, not an empty box',
+    );
+  });
+
+  testWidgets('the minus button never takes a countable amount below 1',
+      (tester) async {
+    await pumpPicker(tester);
+    await tester.tap(find.byKey(const Key('quantity.kind.cob')));
+    await tester.pump();
+    // Two decrements from 1 must clamp at 1, never 0 or blank.
+    await tester.tap(find.byIcon(Icons.remove));
+    await tester.pump();
+    await tester.tap(find.byIcon(Icons.remove));
+    await tester.pump();
+
+    expect(emitted!.count, 1);
+  });
+
+  testWidgets('a vibe unit (a few) carries no number and shows no stepper',
+      (tester) async {
+    await pumpPicker(tester);
+    await tester.tap(find.byKey(const Key('quantity.kind.aFew')));
+    await tester.pump();
+
+    expect(emitted!.kind, QuantityKind.aFew);
+    expect(emitted!.count, isNull);
+    expect(find.byKey(const Key('quantity.count')), findsNothing);
+  });
+
+  testWidgets('typing then clearing the box still stores 1, never empty',
+      (tester) async {
+    await pumpPicker(tester);
+    await tester.tap(find.byKey(const Key('quantity.kind.pod')));
+    await tester.pump();
+    await tester.enterText(find.byKey(const Key('quantity.count')), '');
+    await tester.pump();
+
+    expect(emitted!.kind, QuantityKind.pod);
+    expect(emitted!.count, 1);
+  });
+}