Merge feat/multi-select-groundwork into main (Stage 3A complete)

Add read-only multi-selection state to the product publishing workspace, preparing for future bulk actions without introducing any bulk writes.

Controller (ProductPublishingController):

- Add _multiSelectedIds Set<String> for tracking multi-selected product IDs

- Add toggleMultiSelect(id) to add/remove individual IDs

- Add clearMultiSelection() to deselect all

- Add selectAllVisible() to select all currently visible (filtered/searched) drafts

- Add isMultiSelected(id), multiSelectedIds, multiSelectedCount, isMultiSelectActive getters

- Multi-selection is independent of single-item preview selection

- Multi-selection persists across load cycles and write operations

UI (ProductDraftCard):

- Add optional isMultiSelected/onMultiSelectToggle props

- Show leading Checkbox when multi-select mode is active

- Tapping checkbox toggles multi-select; tapping card body still fires single-item preview

UI (ProductPublishingPage):

- Add _MultiSelectBar widget above product list when multi-select is active

- Shows selected count, Select All button, and Clear button

- Replace deprecated withOpacity() calls with withValues(alpha:)

Tests:

- 15 new multi-select controller tests covering toggle, clear, select-all,

  filter/search interaction, independence from preview selection, persistence

  across loads and writes, and listener notifications

- Total: 262 feature_wordpress tests passing

Validation:

- dart analyze: clean (0 issues)

- flutter test: 262/262 passed

Changed files:

- lib/src/application/product_publishing_controller.dart

- lib/src/presentation/widgets/product_draft_card.dart

- lib/src/presentation/product_publishing_page.dart

- test/product_publishing_controller_test.dart

- docs/development/master_development_brief.md

docs/development/master_development_brief.md

@@ -81,6 +81,7 @@ Rules:
 - ✅ Category-only product edit landed (Stage 1B complete — merged `feat/category-only-edit` → `main` at `8e7e4cb`, 2026-04-11). Stage 1 complete.
 - ✅ Post-write consistency hardening landed (Stage 2A complete — merged `feat/post-write-consistency` → `main` at `7acff83`, 2026-04-11).
 - ✅ Publishing workflow UX hardening landed (Stage 2B complete — merged `feat/publishing-ux-hardening` → `main` at `b81016d`, 2026-04-11). Stage 2 complete.
+- ✅ Multi-select groundwork landed (Stage 3A complete — merged `feat/multi-select-groundwork` → `main`, 2026-05-22).
 
 ### Current narrow edit capabilities on `main`
 
@@ -95,14 +96,14 @@ Rules:
 - `dart analyze` clean
 - `feature_wordpress` tests passing
 - `kell_web` dashboard tests passing
-- latest reported count for `feature_wordpress`: `247/247 passed`
+- latest reported count for `feature_wordpress`: `262/262 passed`
 - latest reported count for `kell_web` dashboard tests: `5/5 passed`
-- baseline commit: `b81016d` (2026-04-11)
+- baseline commit: merge of `feat/multi-select-groundwork` (2026-05-22)
 
 ### Next recommended branch
 
-**`feat/multi-select-groundwork`** — Stage 3A: Multi-select groundwork (read/state only first).
+**`feat/list-efficiency-improvements`** — Stage 3B: List efficiency improvements.
-Branch from `main` at `b81016d`. Stage 2 (operational hardening) is complete.
+Branch from latest `main`. Stage 3A (multi-select groundwork) is complete.
 
 ---
 
@@ -184,24 +185,10 @@ Increase throughput for product triage and management using existing data.
 - `feat/multi-select-groundwork`
 - `feat/list-efficiency-improvements`
 
-#### Stage 3A — Multi-select groundwork (read/state only first)
+#### ~~Stage 3A — Multi-select groundwork (read/state only first)~~ ✅ COMPLETE
 
-##### Goal
+> Merged `feat/multi-select-groundwork` → `main` (2026-05-22).
-
+> Added multi-selection state to `ProductPublishingController` (`toggleMultiSelect`, `clearMultiSelection`, `selectAllVisible`, `isMultiSelected`, `multiSelectedIds`, `multiSelectedCount`). Updated `ProductDraftCard` with optional leading checkbox for multi-select mode. Added `_MultiSelectBar` to `ProductPublishingPage` with selected-count display, Select All, and Clear actions. Single-item preview selection preserved independently. 15 new multi-select tests added (262 total `feature_wordpress` tests passing). No bulk writes introduced.
-Prepare for future bulk actions without implementing bulk writes yet.
-
-##### Requirements
-
-- add selection model for multiple items
-- show selected-count UI
-- allow clear selection
-- preserve current single-item preview behavior where appropriate
-- do not add bulk publish/edit/delete actions yet
-
-##### Definition of done
-
-- multi-select state exists and is tested
-- no bulk writes introduced
 
 #### Stage 3B — List efficiency improvements
 

kell_creations_apps/packages/feature_wordpress/lib/src/application/product_publishing_controller.dart

@@ -157,6 +157,46 @@ class ProductPublishingController extends ChangeNotifier {
   /// Whether the current sort is ascending (`true`) or descending (`false`).
   bool sortAscending = true;
 
+  /// Product IDs that the operator has selected for potential bulk actions.
+  ///
+  /// Multi-select is independent of the single-item [selectedDraft] preview.
+  /// Adding or removing items here does not change which product is shown
+  /// in the detail panel.
+  final Set<String> multiSelectedIds = {};
+
+  /// The number of products currently multi-selected.
+  int get multiSelectedCount => multiSelectedIds.length;
+
+  /// Whether multi-select mode is active (at least one item selected).
+  bool get isMultiSelectActive => multiSelectedIds.isNotEmpty;
+
+  /// Whether the product with [id] is part of the multi-selection.
+  bool isMultiSelected(String id) => multiSelectedIds.contains(id);
+
+  /// Toggles the multi-select state of the product with [id].
+  ///
+  /// If the product is already selected it is removed; otherwise it is added.
+  void toggleMultiSelect(String id) {
+    if (multiSelectedIds.contains(id)) {
+      multiSelectedIds.remove(id);
+    } else {
+      multiSelectedIds.add(id);
+    }
+    _safeNotify();
+  }
+
+  /// Selects all currently visible products (those in [drafts]).
+  void selectAllVisible() {
+    multiSelectedIds.addAll(drafts.map((d) => d.id));
+    _safeNotify();
+  }
+
+  /// Clears the entire multi-selection.
+  void clearMultiSelection() {
+    multiSelectedIds.clear();
+    _safeNotify();
+  }
+
   /// Product IDs that currently have an in-flight status update.
   ///
   /// Used to prevent duplicate clicks and to let the UI show per-row

kell_creations_apps/packages/feature_wordpress/lib/src/presentation/product_publishing_page.dart

@@ -204,6 +204,14 @@ class _ProductPublishingPageState extends State<ProductPublishingPage> {
     return Column(
       crossAxisAlignment: CrossAxisAlignment.start,
       children: [
+        // ── Multi-select action bar ──────────────────────────────────
+        if (controller.isMultiSelectActive)
+          _MultiSelectBar(
+            selectedCount: controller.multiSelectedCount,
+            totalCount: count,
+            onSelectAll: controller.selectAllVisible,
+            onClearSelection: controller.clearMultiSelection,
+          ),
         Padding(
           padding: const EdgeInsets.only(left: KcSpacing.xs, bottom: KcSpacing.sm),
           child: Text(
@@ -223,6 +231,8 @@ class _ProductPublishingPageState extends State<ProductPublishingPage> {
                   draft: draft,
                   isSelected: draft.id == controller.selectedDraft?.id,
                   onTap: () => controller.selectDraft(draft),
+                  isMultiSelected: controller.isMultiSelected(draft.id),
+                  onMultiSelectToggle: () => controller.toggleMultiSelect(draft.id),
                 ),
               );
             },
@@ -262,3 +272,53 @@ class _ProductPublishingPageState extends State<ProductPublishingPage> {
     );
   }
 }
+
+/// A compact action bar shown above the product list when multi-select is
+/// active. Displays the count of selected items and provides Select All /
+/// Clear Selection actions.
+///
+/// No bulk-write actions are included — this is groundwork only.
+class _MultiSelectBar extends StatelessWidget {
+  final int selectedCount;
+  final int totalCount;
+  final VoidCallback onSelectAll;
+  final VoidCallback onClearSelection;
+
+  const _MultiSelectBar({
+    required this.selectedCount,
+    required this.totalCount,
+    required this.onSelectAll,
+    required this.onClearSelection,
+  });
+
+  @override
+  Widget build(BuildContext context) {
+    final allSelected = selectedCount == totalCount;
+
+    return Container(
+      padding: const EdgeInsets.symmetric(horizontal: KcSpacing.sm, vertical: KcSpacing.xs),
+      margin: const EdgeInsets.only(bottom: KcSpacing.sm),
+      decoration: BoxDecoration(
+        color: KcColors.denimBlue.withValues(alpha: 0.08),
+        borderRadius: BorderRadius.circular(8),
+        border: Border.all(color: KcColors.denimBlue.withValues(alpha: 0.3)),
+      ),
+      child: Row(
+        children: [
+          Icon(Icons.checklist, size: 18, color: KcColors.denimBlue),
+          const SizedBox(width: KcSpacing.xs),
+          Text(
+            '$selectedCount selected',
+            style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+              color: KcColors.denimBlue,
+              fontWeight: FontWeight.w600,
+            ),
+          ),
+          const Spacer(),
+          if (!allSelected) TextButton(onPressed: onSelectAll, child: const Text('Select All')),
+          TextButton(onPressed: onClearSelection, child: const Text('Clear')),
+        ],
+      ),
+    );
+  }
+}

kell_creations_apps/packages/feature_wordpress/lib/src/presentation/widgets/product_draft_card.dart

@@ -7,16 +7,36 @@ import 'publish_status_chip.dart';
 /// A card displaying a summary of a [ProductDraft].
 ///
 /// Shows the product name, SKU, price, category, and publish status.
-/// Highlights when [isSelected] is true.
+/// Highlights when [isSelected] is true (single-item preview selection).
+///
+/// When [isMultiSelected] is non-null, a leading checkbox is shown to
+/// support multi-select mode. Tapping the checkbox fires [onMultiSelectToggle];
+/// tapping the rest of the card still fires [onTap] for single-item preview.
 class ProductDraftCard extends StatelessWidget {
   final ProductDraft draft;
   final bool isSelected;
   final VoidCallback? onTap;
 
-  const ProductDraftCard({super.key, required this.draft, this.isSelected = false, this.onTap});
+  /// Whether this card is part of the multi-selection.
+  /// When `null`, the checkbox is hidden (multi-select not active).
+  final bool? isMultiSelected;
+
+  /// Called when the multi-select checkbox is toggled.
+  final VoidCallback? onMultiSelectToggle;
+
+  const ProductDraftCard({
+    super.key,
+    required this.draft,
+    this.isSelected = false,
+    this.onTap,
+    this.isMultiSelected,
+    this.onMultiSelectToggle,
+  });
 
   @override
   Widget build(BuildContext context) {
+    final showCheckbox = isMultiSelected != null;
+
     return GestureDetector(
       onTap: onTap,
       child: AnimatedContainer(
@@ -33,43 +53,61 @@ class ProductDraftCard extends StatelessWidget {
             BoxShadow(blurRadius: 8, offset: Offset(0, 2), color: Color(0x11000000)),
           ],
         ),
-        child: Column(
+        child: Row(
           crossAxisAlignment: CrossAxisAlignment.start,
           children: [
-            Text(
+            if (showCheckbox) ...[
-              draft.name,
+              Checkbox(
-              style: Theme.of(context).textTheme.titleLarge,
+                value: isMultiSelected ?? false,
-              maxLines: 1,
+                onChanged: (_) => onMultiSelectToggle?.call(),
-              overflow: TextOverflow.ellipsis,
+              ),
-            ),
+              const SizedBox(width: KcSpacing.xs),
-            const SizedBox(height: KcSpacing.xs),
+            ],
-            Text('SKU: ${draft.sku}', style: Theme.of(context).textTheme.bodyMedium),
+            Expanded(
-            const SizedBox(height: KcSpacing.sm),
+              child: Column(
-            Row(
+                crossAxisAlignment: CrossAxisAlignment.start,
-              children: [
+                children: [
-                Text(
+                  Text(
-                  '\$${draft.price.toStringAsFixed(2)}',
+                    draft.name,
-                  style: Theme.of(
+                    style: Theme.of(context).textTheme.titleLarge,
-                    context,
+                    maxLines: 1,
-                  ).textTheme.bodyLarge?.copyWith(fontWeight: FontWeight.w600),
+                    overflow: TextOverflow.ellipsis,
-                ),
+                  ),
-                const SizedBox(width: KcSpacing.sm),
+                  const SizedBox(height: KcSpacing.xs),
-                Text(
+                  Text('SKU: ${draft.sku}', style: Theme.of(context).textTheme.bodyMedium),
-                  draft.category,
+                  const SizedBox(height: KcSpacing.sm),
-                  style: Theme.of(context).textTheme.bodyMedium?.copyWith(color: KcColors.neutral),
+                  Row(
-                ),
+                    children: [
-              ],
+                      Text(
-            ),
+                        '\$${draft.price.toStringAsFixed(2)}',
-            const Spacer(),
+                        style: Theme.of(
-            Row(
+                          context,
-              mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                        ).textTheme.bodyLarge?.copyWith(fontWeight: FontWeight.w600),
-              children: [
+                      ),
-                PublishStatusChip(status: draft.status),
+                      const SizedBox(width: KcSpacing.sm),
-                Text(
+                      Text(
-                  '${draft.lastModified.year}-${draft.lastModified.month.toString().padLeft(2, '0')}-${draft.lastModified.day.toString().padLeft(2, '0')}',
+                        draft.category,
-                  style: Theme.of(context).textTheme.bodySmall?.copyWith(color: KcColors.neutral),
+                        style: Theme.of(
-                ),
+                          context,
-              ],
+                        ).textTheme.bodyMedium?.copyWith(color: KcColors.neutral),
+                      ),
+                    ],
+                  ),
+                  const Spacer(),
+                  Row(
+                    mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                    children: [
+                      PublishStatusChip(status: draft.status),
+                      Text(
+                        '${draft.lastModified.year}-${draft.lastModified.month.toString().padLeft(2, '0')}-${draft.lastModified.day.toString().padLeft(2, '0')}',
+                        style: Theme.of(
+                          context,
+                        ).textTheme.bodySmall?.copyWith(color: KcColors.neutral),
+                      ),
+                    ],
+                  ),
+                ],
+              ),
             ),
           ],
         ),

kell_creations_apps/packages/feature_wordpress/test/product_publishing_controller_test.dart

@@ -1017,6 +1017,203 @@ void main() {
       });
     });
 
+    // ── Multi-select groundwork ─────────────────────────────────────────
+
+    group('multiSelect', () {
+      test('starts with empty multi-selection', () {
+        expect(controller.multiSelectedIds, isEmpty);
+        expect(controller.multiSelectedCount, 0);
+        expect(controller.isMultiSelectActive, false);
+      });
+
+      test('toggleMultiSelect adds an id', () async {
+        await controller.load();
+
+        controller.toggleMultiSelect('1');
+
+        expect(controller.isMultiSelected('1'), true);
+        expect(controller.multiSelectedCount, 1);
+        expect(controller.isMultiSelectActive, true);
+      });
+
+      test('toggleMultiSelect removes an already-selected id', () async {
+        await controller.load();
+
+        controller.toggleMultiSelect('1');
+        expect(controller.isMultiSelected('1'), true);
+
+        controller.toggleMultiSelect('1');
+        expect(controller.isMultiSelected('1'), false);
+        expect(controller.multiSelectedCount, 0);
+        expect(controller.isMultiSelectActive, false);
+      });
+
+      test('multiple ids can be multi-selected', () async {
+        await controller.load();
+
+        controller.toggleMultiSelect('1');
+        controller.toggleMultiSelect('3');
+        controller.toggleMultiSelect('5');
+
+        expect(controller.multiSelectedCount, 3);
+        expect(controller.isMultiSelected('1'), true);
+        expect(controller.isMultiSelected('3'), true);
+        expect(controller.isMultiSelected('5'), true);
+        expect(controller.isMultiSelected('2'), false);
+      });
+
+      test('clearMultiSelection removes all multi-selected ids', () async {
+        await controller.load();
+
+        controller.toggleMultiSelect('1');
+        controller.toggleMultiSelect('2');
+        controller.toggleMultiSelect('3');
+        expect(controller.multiSelectedCount, 3);
+
+        controller.clearMultiSelection();
+
+        expect(controller.multiSelectedIds, isEmpty);
+        expect(controller.multiSelectedCount, 0);
+        expect(controller.isMultiSelectActive, false);
+      });
+
+      test('selectAllVisible selects all visible draft ids', () async {
+        await controller.load();
+
+        controller.selectAllVisible();
+
+        expect(controller.multiSelectedCount, 6);
+        for (final draft in controller.drafts) {
+          expect(controller.isMultiSelected(draft.id), true);
+        }
+      });
+
+      test('selectAllVisible respects active filter', () async {
+        await controller.load();
+
+        controller.setFilter('draft');
+        expect(controller.drafts.length, 2);
+
+        controller.selectAllVisible();
+
+        expect(controller.multiSelectedCount, 2);
+        expect(controller.isMultiSelected('4'), true);
+        expect(controller.isMultiSelected('5'), true);
+        // Non-visible ids should not be selected.
+        expect(controller.isMultiSelected('1'), false);
+      });
+
+      test('multi-select is independent of single-item preview selection', () async {
+        await controller.load();
+
+        // Multi-select two items.
+        controller.toggleMultiSelect('1');
+        controller.toggleMultiSelect('3');
+
+        // Single-select a different item for preview.
+        controller.selectDraft(controller.drafts.firstWhere((d) => d.id == '5'));
+
+        // Preview selection should be independent.
+        expect(controller.selectedDraft!.id, '5');
+        expect(controller.isMultiSelected('5'), false);
+        expect(controller.multiSelectedCount, 2);
+      });
+
+      test('multi-selection persists across load cycles', () async {
+        await controller.load();
+
+        controller.toggleMultiSelect('2');
+        controller.toggleMultiSelect('4');
+
+        await controller.load();
+
+        expect(controller.isMultiSelected('2'), true);
+        expect(controller.isMultiSelected('4'), true);
+        expect(controller.multiSelectedCount, 2);
+      });
+
+      test('multi-selection persists after write operations', () async {
+        await controller.load();
+
+        controller.toggleMultiSelect('1');
+        controller.toggleMultiSelect('4');
+
+        // Update price on product 4.
+        await controller.updatePrice('4', 20.00);
+
+        // Multi-selection should still be intact.
+        expect(controller.isMultiSelected('1'), true);
+        expect(controller.isMultiSelected('4'), true);
+        expect(controller.multiSelectedCount, 2);
+      });
+
+      test('toggleMultiSelect notifies listeners', () async {
+        await controller.load();
+
+        int notifyCount = 0;
+        controller.addListener(() => notifyCount++);
+
+        controller.toggleMultiSelect('1');
+        expect(notifyCount, 1);
+
+        controller.toggleMultiSelect('1');
+        expect(notifyCount, 2);
+      });
+
+      test('clearMultiSelection notifies listeners', () async {
+        await controller.load();
+
+        controller.toggleMultiSelect('1');
+
+        int notifyCount = 0;
+        controller.addListener(() => notifyCount++);
+
+        controller.clearMultiSelection();
+        expect(notifyCount, 1);
+      });
+
+      test('selectAllVisible notifies listeners', () async {
+        await controller.load();
+
+        int notifyCount = 0;
+        controller.addListener(() => notifyCount++);
+
+        controller.selectAllVisible();
+        expect(notifyCount, 1);
+      });
+
+      test('selectAllVisible with search selects only matching products', () async {
+        await controller.load();
+
+        controller.setSearchQuery('coaster');
+        expect(controller.drafts.length, 2);
+
+        controller.selectAllVisible();
+
+        expect(controller.multiSelectedCount, 2);
+        expect(controller.isMultiSelected('2'), true); // Citrus Coaster Set
+        expect(controller.isMultiSelected('6'), true); // Sublimated Slate Coaster
+        expect(controller.isMultiSelected('1'), false);
+      });
+
+      test('selectAllVisible is additive to existing selection', () async {
+        await controller.load();
+
+        // Select one product manually.
+        controller.toggleMultiSelect('1');
+
+        // Filter to drafts only and select all visible.
+        controller.setFilter('draft');
+        controller.selectAllVisible();
+
+        // Should have the manually selected + the two drafts.
+        expect(controller.isMultiSelected('1'), true);
+        expect(controller.isMultiSelected('4'), true);
+        expect(controller.isMultiSelected('5'), true);
+        expect(controller.multiSelectedCount, 3);
+      });
+    });
+
     group('disposed guard', () {
       test('load does not notify after disposal', () async {
         // Start load, then immediately dispose.