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>

CHANGELOG.md

@@ -18,6 +18,14 @@ heading, and (b) bumping `pubspec.yaml` `version:` in the same commit.
 
 ### Added
 
+- **Vim ex command-line (`:`).** Under the Vim preset, `:` opens a transient
+  one-line overlay running a fixed table — `:w` save, `:q` close the active tab
+  (the split self-collapses on the last one), `:wq`/`:x` and `ZZ` save+close,
+  `:e <path>` jump to quick-open seeded with the path, `:<n>` goto-line. Unknown
+  commands flash and stay open; with no active buffer it no-ops. Opens from the
+  editor or a focused pane; Esc dismisses. Adds the `editor.goto-line` CLI/IPC
+  verb. (T-407)
+
 - **Crash-survivable logging.** clide writes a durable JSON-lines log to a
   persistent per-platform dir (Windows `%LOCALAPPDATA%`, macOS `~/Library/Logs`,
   Linux `$XDG_STATE_HOME`), fsyncing warn/error + pty/ffi records immediately so