dissolve app/ into repo root (D-056)

Single Flutter package at the repo root. All code, tests, assets,
and platform directories moved from app/ to root. Package renamed
from clide_app to clide — all imports rewritten. Merged pubspec
combines core (ffi) and app (flutter, yaml, xterm) dependencies.
Makefile simplified: no APP_PRESENT conditionals, no cd, no daemon
lifecycle. 317 tests pass.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

test/kernel/src/settings_test.dart

@@ -0,0 +1,94 @@
+import 'dart:io';
+
+import 'package:clide/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));
+    });
+  });
+}