feat(vim): ex command-line overlay (:w :q :wq :x :e :N, ZZ) (T-407)

Under the Vim preset, `:` opens a transient one-line ex overlay running a
fixed v1 table; ZZ runs :wq directly. Completes the last built child of the
T-403 cross-pane vim layer (T-405 part 2 gt/gT still open).

- ExLineController + parseExCommand grammar + editor-targeted executors
  (lib/kernel/src/ex_line.dart); the overlay (lib/widgets/src/ex_line_overlay
  .dart) reuses the quick-open chrome, mounts in the root_shell Stack, and
  publishes the exline.open scope flag. Unknown commands flash + stay open;
  with no active buffer every command no-ops (2026-06-13 decision).
- :q closes the active tab via editor.close on its id — the registry promotes
  the next buffer and the split self-collapses on the last (2026-06-12
  decision); :w/:wq/:x/ZZ save (+close) the active buffer.
- :e <path> seeds quick-open (new QuickOpenController.open(seed:)); :N adds the
  editor.goto-line IPC/CLI verb (reuses _offsetForLine). Goto needs caret sync:
  EditorController now handles editor.selection-changed and the editor view
  moves the caret on a selection-only change.
- `:` and ZZ are typed intents; the editor matcher and PaneKeyNav now bubble
  unhandled typed intents to the app-root Actions, so they fire from any focus.
  vim.yaml binds `:`, ZZ (shift+z shift+z), and Esc-dismiss.

Tests: parser/controller/executors, editor.goto-line daemon tests,
selection-changed (controller + view), full overlay widget test. make test
green; analyze + format clean.

Also files T-441 (drop bold from the ticket-id card label) and T-442
(sub-agent renders as 3 cards instead of one bundle) under the T-276 UI epic.

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

test/builtin/editor/editor_controller_test.dart

@@ -187,6 +187,59 @@ void main() {
       expect(c.activeId, isNull); // cleared until an active-changed arrives
     });
 
+    test('editor.selection-changed mirrors an external caret move onto the active buffer (T-407)', () async {
+      ipc.stub(
+        'editor.list',
+        (_) async => _ok({
+          'buffers': [_buf('b_1', 'a.dart')],
+        }),
+      );
+      ipc.stub(
+        'editor.active',
+        (_) async => _ok({
+          'active': {'id': 'b_1'},
+        }),
+      );
+      ipc.stub('editor.read', (_) async => _ok(_read('b_1', 'a.dart', 'line1\nline2')));
+      await c.hydrate();
+      expect(c.selection.start, 0);
+
+      // An external setSelection (ex-line :N goto) jumps the caret server-side.
+      emitEditor(bus, 'editor.selection-changed', {
+        'id': 'b_1',
+        'selection': {'start': 6, 'end': 6},
+      });
+      await pumpEventQueue();
+
+      expect(c.selection.start, 6);
+      expect(c.selection.end, 6);
+    });
+
+    test('editor.selection-changed for a non-active buffer is ignored', () async {
+      ipc.stub(
+        'editor.list',
+        (_) async => _ok({
+          'buffers': [_buf('b_1', 'a.dart')],
+        }),
+      );
+      ipc.stub(
+        'editor.active',
+        (_) async => _ok({
+          'active': {'id': 'b_1'},
+        }),
+      );
+      ipc.stub('editor.read', (_) async => _ok(_read('b_1', 'a.dart', 'hello')));
+      await c.hydrate();
+
+      emitEditor(bus, 'editor.selection-changed', {
+        'id': 'b_other',
+        'selection': {'start': 3, 'end': 3},
+      });
+      await pumpEventQueue();
+
+      expect(c.selection.start, 0); // untouched
+    });
+
     test('editor.saved clears the dirty marker on the buffer', () async {
       ipc.stub(
         'editor.list',

test/builtin/editor/editor_view_test.dart

@@ -6,6 +6,7 @@ library;
 
 import 'package:clide/builtin/editor/src/editor_view.dart';
 import 'package:clide/clide.dart';
+import 'package:clide/kernel/kernel.dart';
 import 'package:clide/widgets/widgets.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
@@ -76,6 +77,32 @@ void main() {
       expect(find.text('Open a file to begin editing.'), findsOneWidget);
     });
 
+    testWidgets('an external selection-changed moves the caret without retyping (T-407)', (tester) async {
+      stubBuffers([_buf('b_1', 'lib/a.dart')], active: 'b_1');
+      await tester.pumpWidget(harness(f, const EditorView()));
+      await tester.pumpAndSettle();
+      expect(tester.widget<EditableText>(find.byType(EditableText)).controller.selection.baseOffset, 0);
+
+      // An ex-line `:N` goto sets the selection server-side; the buffer content
+      // is unchanged, so only the caret should move (the selection-only branch).
+      f.services.events.emit(
+        DaemonEvent(
+          subsystem: 'editor',
+          kind: 'editor.selection-changed',
+          data: const {
+            'id': 'b_1',
+            'selection': {'start': 5, 'end': 5},
+          },
+          ts: DateTime.now().toUtc(),
+        ),
+      );
+      await tester.pumpAndSettle();
+
+      final field = tester.widget<EditableText>(find.byType(EditableText));
+      expect(field.controller.selection.baseOffset, 5);
+      expect(field.controller.text, 'content of lib/a.dart'); // unchanged
+    });
+
     testWidgets('tapping an inactive tab routes to editor.activate', (tester) async {
       stubBuffers([_buf('b_1', 'lib/a.dart'), _buf('b_2', 'src/b.dart')], active: 'b_1');
       String? activated;