add clide status orientation snapshot; close Epic C (T-221)

clide status returns a one-shot snapshot for an orienting agent: the
workspace root, a git summary (branch/ahead/behind/clean/counts), the
active editor buffer + selection, the read-only readers' viewed docs
(new ReaderNavRegistry.currentByReader, the T-220 fold), focusedFile,
the live view-pane list (T-219), and the layout (slots + visibility +
focus mode). Previously 'status' was an unknown command (exit 3).

The verb handler (status_command.dart) is a thin Flutter-free wrapper;
the snapshot is assembled in main.dart where the live kernel + subsystem
state is in scope, with readerNav captured post-boot. Composite shape is
verified live; the pieces are unit-tested.

Closes T-221 and T-218 (Epic C) under T-208 'Give Claude hands' --
the observe half of D-6 parity is now in place.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

test/daemon/status_command_test.dart

@@ -0,0 +1,43 @@
+/// Tests for the `status` command verb (T-221). The snapshot *contents*
+/// are assembled in main.dart from live kernel state (verified live); here
+/// we cover the dispatch mechanics: the verb resolves (no longer exit 3),
+/// returns the assembled map with exit 0, and is recomputed per request.
+library;
+
+import 'package:clide/clide.dart';
+import 'package:clide/src/daemon/status_command.dart';
+import 'package:test/test.dart';
+
+void main() {
+  IpcRequest req() => IpcRequest(id: '1', cmd: 'status', args: const {});
+
+  test('status resolves and returns the assembled snapshot with exit 0', () async {
+    final d = DaemonDispatcher();
+    registerStatusCommand(
+        d,
+        () async => {
+              'workspace': '/repo',
+              'focusedFile': null,
+              'panes': const [],
+            });
+    final r = await d.dispatch(req());
+    expect(r.ok, isTrue);
+    expect(r.data['workspace'], '/repo');
+    expect(r.data['panes'], isEmpty);
+  });
+
+  test('the snapshot is recomputed on every call (live, not cached)', () async {
+    var n = 0;
+    final d = DaemonDispatcher();
+    registerStatusCommand(d, () async => {'n': ++n});
+    expect((await d.dispatch(req())).data['n'], 1);
+    expect((await d.dispatch(req())).data['n'], 2);
+  });
+
+  test('without registration, status is an unknown command (exit 3 / notFound)', () async {
+    final d = DaemonDispatcher();
+    final r = await d.dispatch(req());
+    expect(r.ok, isFalse);
+    expect(r.error?.kind, IpcErrorKind.notFound);
+  });
+}