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>

lib/kernel/src/commands/keybindings.dart

@@ -0,0 +1,78 @@
+import 'package:flutter/foundation.dart';
+import 'package:flutter/services.dart';
+
+/// Key combo: modifiers + primary key. Canonicalized on construction
+/// (modifiers sorted, lowercased) so equality works for lookup keys.
+@immutable
+class Keybinding {
+  Keybinding({required Set<String> modifiers, required String key})
+      : modifiers = _canonModifiers(modifiers),
+        key = key.toLowerCase();
+
+  final List<String> modifiers;
+  final String key;
+
+  static List<String> _canonModifiers(Set<String> m) {
+    final normalized = m.map((s) => s.toLowerCase()).toSet().toList()..sort();
+    return List.unmodifiable(normalized);
+  }
+
+  /// Parse "ctrl+shift+g", "cmd+k", "alt+f4".
+  static Keybinding parse(String spec) {
+    if (spec.trim().isEmpty) {
+      throw ArgumentError('empty keybinding');
+    }
+    final parts = spec.split('+').map((s) => s.trim()).toList();
+    final key = parts.removeLast();
+    if (key.isEmpty) {
+      throw ArgumentError('keybinding is missing a key: "$spec"');
+    }
+    return Keybinding(modifiers: parts.toSet(), key: key);
+  }
+
+  String get canonical {
+    if (modifiers.isEmpty) return key;
+    return '${modifiers.join('+')}+$key';
+  }
+
+  @override
+  bool operator ==(Object other) =>
+      other is Keybinding &&
+      other.key == key &&
+      listEquals(other.modifiers, modifiers);
+
+  @override
+  int get hashCode => Object.hash(key, Object.hashAll(modifiers));
+
+  @override
+  String toString() => 'Keybinding($canonical)';
+}
+
+class KeybindingResolver {
+  final Map<Keybinding, String> _bindings = {};
+
+  void bind(Keybinding b, String commandId) {
+    _bindings[b] = commandId;
+  }
+
+  void unbind(Keybinding b) {
+    _bindings.remove(b);
+  }
+
+  String? commandFor(Keybinding b) => _bindings[b];
+
+  Iterable<MapEntry<Keybinding, String>> get entries => _bindings.entries;
+
+  /// Map a Flutter [KeyEvent] to a [Keybinding] suitable for lookup.
+  static Keybinding? fromKeyEvent(KeyEvent event, HardwareKeyboard keyboard) {
+    if (event is! KeyDownEvent) return null;
+    final label = event.logicalKey.keyLabel;
+    if (label.isEmpty) return null;
+    final mods = <String>{};
+    if (keyboard.isControlPressed) mods.add('ctrl');
+    if (keyboard.isShiftPressed) mods.add('shift');
+    if (keyboard.isAltPressed) mods.add('alt');
+    if (keyboard.isMetaPressed) mods.add('cmd');
+    return Keybinding(modifiers: mods, key: label);
+  }
+}

lib/kernel/src/commands/palette.dart

@@ -0,0 +1,50 @@
+import 'package:clide/extension/src/contribution.dart';
+import 'package:clide/kernel/src/commands/registry.dart';
+import 'package:flutter/foundation.dart';
+
+class PaletteController extends ChangeNotifier {
+  PaletteController(this._registry);
+
+  final CommandRegistry _registry;
+
+  bool _open = false;
+  String _filter = '';
+
+  bool get isOpen => _open;
+  String get filter => _filter;
+
+  void open() {
+    if (_open) return;
+    _open = true;
+    notifyListeners();
+  }
+
+  void close() {
+    if (!_open) return;
+    _open = false;
+    _filter = '';
+    notifyListeners();
+  }
+
+  void toggle() => _open ? close() : open();
+
+  void setFilter(String f) {
+    if (_filter == f) return;
+    _filter = f;
+    notifyListeners();
+  }
+
+  List<CommandContribution> filtered() {
+    if (_filter.isEmpty) return _registry.all.toList();
+    final q = _filter.toLowerCase();
+    return _registry.all.where((c) {
+      final haystack = (c.title ?? c.command).toLowerCase();
+      return haystack.contains(q);
+    }).toList();
+  }
+
+  Future<void> invoke(String command) async {
+    close();
+    await _registry.execute(command);
+  }
+}

lib/kernel/src/commands/registry.dart

@@ -0,0 +1,37 @@
+import 'package:clide/clide.dart';
+import 'package:clide/extension/src/contribution.dart';
+import 'package:flutter/foundation.dart';
+
+class CommandRegistry extends ChangeNotifier {
+  final Map<String, CommandContribution> _byCommand = {};
+
+  void register(CommandContribution cmd) {
+    _byCommand[cmd.command] = cmd;
+    notifyListeners();
+  }
+
+  void unregister(String command) {
+    if (_byCommand.remove(command) != null) notifyListeners();
+  }
+
+  Iterable<CommandContribution> get all => _byCommand.values;
+  CommandContribution? get(String command) => _byCommand[command];
+
+  Future<IpcResponse> execute(
+    String command, {
+    List<String> args = const [],
+  }) async {
+    final c = _byCommand[command];
+    if (c == null) {
+      return IpcResponse.err(
+        id: '',
+        error: IpcError(
+          code: IpcExitCode.notFound,
+          kind: IpcErrorKind.notFound,
+          message: 'no such command: $command',
+        ),
+      );
+    }
+    return c.run(args);
+  }
+}