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/kernel/src/settings_test.dart

@@ -0,0 +1,94 @@
+import 'dart:io';
+
+import 'package:clide_app/kernel/kernel.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group('SettingsStore', () {
+    late Directory tmp;
+    late SettingsStore store;
+
+    setUp(() async {
+      tmp = await Directory.systemTemp.createTemp('clide_settings_');
+      store = SettingsStore(appDir: tmp);
+      await store.load();
+    });
+
+    tearDown(() async {
+      store.dispose();
+      if (await tmp.exists()) {
+        try {
+          await tmp.delete(recursive: true);
+        } catch (_) {}
+      }
+    });
+
+    test('scope key validation — rejects non-standard prefixes', () async {
+      expect(
+        () => store.get<String>('nothing.here'),
+        throwsA(isA<ArgumentError>()),
+      );
+      expect(
+        () => store.set('notascope.key', 'v'),
+        throwsA(isA<ArgumentError>()),
+      );
+    });
+
+    test('app.* scope round-trips via YAML on disk', () async {
+      await store.set<String>('app.theme.current', 'summer-night');
+      expect(store.get<String>('app.theme.current'), 'summer-night');
+      final loaded = SettingsStore(appDir: tmp);
+      await loaded.load();
+      expect(loaded.get<String>('app.theme.current'), 'summer-night');
+      loaded.dispose();
+    });
+
+    test('app.* scope supports bool + int + list', () async {
+      await store.set<bool>('app.extensions.git.enabled', false);
+      await store.set<int>('app.layout.width', 240);
+      await store.set<List<String>>('app.recent', const ['/a', '/b']);
+      final loaded = SettingsStore(appDir: tmp);
+      await loaded.load();
+      expect(loaded.get<bool>('app.extensions.git.enabled'), false);
+      expect(loaded.get<int>('app.layout.width'), 240);
+      expect(loaded.get<List<dynamic>>('app.recent'), ['/a', '/b']);
+      loaded.dispose();
+    });
+
+    test('setting a project.* key without an open project throws', () async {
+      expect(
+        () => store.set('project.thing', 'x'),
+        throwsA(isA<StateError>()),
+      );
+    });
+
+    test('project scope is isolated from app scope', () async {
+      final projectDir = await Directory.systemTemp.createTemp('clide_proj_');
+      try {
+        await store.setProjectDir(projectDir);
+        await store.set<String>('app.global', 'A');
+        await store.set<String>('project.scoped', 'P');
+        expect(store.get<String>('app.global'), 'A');
+        expect(store.get<String>('project.scoped'), 'P');
+        // Reload project dir (simulate reopening) and confirm app values
+        // don't leak into project store.
+        await store.setProjectDir(null);
+        expect(store.get<String>('app.global'), 'A');
+        expect(store.get<String>('project.scoped'), isNull);
+        await store.setProjectDir(projectDir);
+        expect(store.get<String>('project.scoped'), 'P');
+      } finally {
+        try {
+          await projectDir.delete(recursive: true);
+        } catch (_) {}
+      }
+    });
+
+    test('notifyListeners fires on set and load', () async {
+      var count = 0;
+      store.addListener(() => count++);
+      await store.set<String>('app.k', 'v');
+      expect(count, greaterThanOrEqualTo(1));
+    });
+  });
+}