add panel.resize CLI verb (T-119)

The keyboard half of panel resizing landed in T-111 (arrow-key
splitters); this completes D-6 user/Claude parity with a CLI verb now
that T-99's IPC dispatch path exists. `clide panel resize <slot> --to N`
sets an absolute pixel size, `--by N` nudges relative to current, and
the reserved `editor` slot drives the editor/bottom-panel split ratio.

The handler lives in panel_commands.dart and stays Flutter-free (so
test/daemon/ keeps running under `dart test`) by talking to an abstract
PanelResizer; the kernel bridge in panel_resizer_kernel.dart wraps
LayoutArrangement and reuses T-111's bumpedSlotSize so the CLI's
relative deltas honour the same right-edge sign-flip as the drag/arrow
handlers. Arguments are lifted from both the direct call shape and the
argv-translator's positional/flags shape pending the typed schema in
T-120. The daemonClientFactory now receives the LayoutArrangement so
the dispatcher can reach it.

Co-Authored-By: Claude <noreply@anthropic.com>

CHANGELOG.md

@@ -18,6 +18,9 @@ heading, and (b) bumping `pubspec.yaml` `version:` in the same commit.
 
 ### Added
 
+- `clide panel resize <slot>` CLI verb (T-119) — set an absolute size
+  with `--to` or nudge with `--by`; `editor` targets the split ratio.
+  Completes user/Claude parity (D-6) with T-111's keyboard resize.
 - Unix-domain IPC socket server in the Flutter app (T-99 / T-124).
   Per-workspace path (D-70: `$XDG_RUNTIME_DIR/clide/<hash>.sock` on
   Linux, `~/Library/Caches/clide/<hash>.sock` on macOS). 0600 socket