add app test suite — unit, widget, golden, a11y (168 tests)

Four layers under app/test/:

  * kernel/, extension/ — unit tests for every kernel service and
    the extension contract. i18n fallback chain gets the full
    matrix (exact/lang/default/placeholder, namespace isolation,
    unknown namespace, interpolation). Theme resolver and
    extension-manager topo sort covered.
  * widgets/, builtin/ — widget tests for every primitive and each
    Tier 0 built-in. Assertions reach into the Semantics node so
    a missing label fails structurally, not visually.
  * goldens/ — Alchemist + Ahem font for cross-platform pixel
    stability; primitives only (button, tab bar, icon set). No
    goldens for compositions — they'd churn through every tier.
  * a11y/ — contract-level gate: semantic coverage walks the
    built-in catalogue, contrast walks every token pair in every
    bundled theme against WCAG-AA thresholds (catches real
    regressions: the first run caught `tab.inactive_text` at 2.81
    in summer-night), i18n coverage asserts every referenced key
    exists in its catalog (exists-in-map, not "key == value" — too
    ambiguous for keys that happen to equal their translation).

Helpers under helpers/: `KernelFixture.create()` boots a
KernelServices with in-memory stores + a FakeDaemonClient (no
socket, drivable connected-state), `widget_harness` wraps a
widget in the minimum tree that resolves theme + i18n.

Co-Authored-By: Claude <noreply@anthropic.com>

app/test/goldens/clide_button_goldens_test.dart

@@ -0,0 +1,85 @@
+import 'package:alchemist/alchemist.dart';
+import 'package:clide_app/widgets/widgets.dart';
+import 'package:flutter/widgets.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import '../helpers/kernel_fixture.dart';
+import '../helpers/widget_harness.dart';
+
+void main() {
+  late KernelFixture f;
+
+  setUp(() async => f = await KernelFixture.create());
+  tearDown(() async => f.dispose());
+
+  goldenTest(
+    'ClideButton variants + states',
+    fileName: 'clide_button',
+    pumpBeforeTest: (tester) async {
+      // wait for hover/press state to settle
+      await tester.pump(const Duration(milliseconds: 50));
+    },
+    builder: () => GoldenTestGroup(
+      columns: 3,
+      children: [
+        GoldenTestScenario(
+          name: 'normal / enabled',
+          child: _wrap(f, ClideButton(label: 'Save', onPressed: () {})),
+        ),
+        GoldenTestScenario(
+          name: 'normal / disabled',
+          child: _wrap(f, const ClideButton(label: 'Save', onPressed: null)),
+        ),
+        GoldenTestScenario(
+          name: 'primary / enabled',
+          child: _wrap(
+            f,
+            ClideButton(
+              label: 'Commit',
+              onPressed: () {},
+              variant: ClideButtonVariant.primary,
+            ),
+          ),
+        ),
+        GoldenTestScenario(
+          name: 'primary / disabled',
+          child: _wrap(
+            f,
+            const ClideButton(
+              label: 'Commit',
+              onPressed: null,
+              variant: ClideButtonVariant.primary,
+            ),
+          ),
+        ),
+        GoldenTestScenario(
+          name: 'subtle / enabled',
+          child: _wrap(
+            f,
+            ClideButton(
+              label: 'Open',
+              onPressed: () {},
+              variant: ClideButtonVariant.subtle,
+            ),
+          ),
+        ),
+        GoldenTestScenario(
+          name: 'subtle / disabled',
+          child: _wrap(
+            f,
+            const ClideButton(
+              label: 'Open',
+              onPressed: null,
+              variant: ClideButtonVariant.subtle,
+            ),
+          ),
+        ),
+      ],
+    ),
+  );
+}
+
+Widget _wrap(KernelFixture f, Widget child) => SizedBox(
+      width: 140,
+      child: harness(f, child),
+    );

app/test/goldens/clide_icon_goldens_test.dart

@@ -0,0 +1,44 @@
+import 'package:alchemist/alchemist.dart';
+import 'package:clide_app/widgets/widgets.dart';
+import 'package:flutter/widgets.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import '../helpers/kernel_fixture.dart';
+import '../helpers/widget_harness.dart';
+
+void main() {
+  late KernelFixture f;
+  setUp(() async => f = await KernelFixture.create());
+  tearDown(() async => f.dispose());
+
+  goldenTest(
+    'ClideIcon painter set',
+    fileName: 'clide_icon',
+    builder: () => GoldenTestGroup(
+      columns: 4,
+      children: [
+        for (final pair in const [
+          ('folder', FolderIcon()),
+          ('gear', GearIcon()),
+          ('close', CloseIcon()),
+          ('chevron-right', ChevronRightIcon()),
+          ('chevron-down', ChevronDownIcon()),
+          ('dot', DotIcon()),
+          ('check', CheckIcon()),
+          ('plug', PlugIcon()),
+        ])
+          GoldenTestScenario(
+            name: pair.$1,
+            child: harness(
+              f,
+              SizedBox(
+                width: 24,
+                height: 24,
+                child: ClideIcon(pair.$2, size: 24),
+              ),
+            ),
+          ),
+      ],
+    ),
+  );
+}

app/test/goldens/clide_tab_bar_goldens_test.dart

@@ -0,0 +1,60 @@
+import 'package:alchemist/alchemist.dart';
+import 'package:clide_app/widgets/widgets.dart';
+import 'package:flutter/widgets.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+import '../helpers/kernel_fixture.dart';
+import '../helpers/widget_harness.dart';
+
+void main() {
+  late KernelFixture f;
+
+  setUp(() async => f = await KernelFixture.create());
+  tearDown(() async => f.dispose());
+
+  goldenTest(
+    'ClideTabBar active / inactive',
+    fileName: 'clide_tab_bar',
+    builder: () => GoldenTestGroup(
+      columns: 1,
+      children: [
+        GoldenTestScenario(
+          name: 'first tab active',
+          child: SizedBox(
+            width: 320,
+            child: harness(
+              f,
+              ClideTabBar(
+                items: const [
+                  ClideTabItem(id: 'files', title: 'Files'),
+                  ClideTabItem(id: 'git', title: 'Git'),
+                  ClideTabItem(id: 'tree', title: 'Tree'),
+                ],
+                activeId: 'files',
+                onSelect: (_) {},
+              ),
+            ),
+          ),
+        ),
+        GoldenTestScenario(
+          name: 'middle tab active',
+          child: SizedBox(
+            width: 320,
+            child: harness(
+              f,
+              ClideTabBar(
+                items: const [
+                  ClideTabItem(id: 'files', title: 'Files'),
+                  ClideTabItem(id: 'git', title: 'Git'),
+                  ClideTabItem(id: 'tree', title: 'Tree'),
+                ],
+                activeId: 'git',
+                onSelect: (_) {},
+              ),
+            ),
+          ),
+        ),
+      ],
+    ),
+  );
+}