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>

lib/builtin/editor/src/editor_controller.dart

@@ -204,6 +204,19 @@ class EditorController extends ChangeNotifier {
           _dirty = false;
           notifyListeners();
         }
+      case 'editor.selection-changed':
+        // An external setSelection moved the caret server-side (find-in-files
+        // line jump, ex-line `:N` goto — T-407). Mirror it onto the active
+        // buffer so the view's caret follows. Skipped while our own local edits
+        // are in flight — their echo already carries the authoritative caret.
+        final id = e.data['id'] as String?;
+        if (id != null && id == _activeId && _pendingLocalEdits == 0) {
+          final sel = e.data['selection'];
+          if (sel is Map) {
+            _selection = Selection.fromJson(sel.cast<String, Object?>());
+            notifyListeners();
+          }
+        }
       case 'editor.settings-changed':
         // A source (e.g. a saved .editorconfig) re-resolved the buffer's
         // settings. Refresh the active buffer's copy so indent/ruler update.