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>

.pql/changelog/ticket_history/2026-05.sql

@@ -1891,3 +1891,4 @@ Design still open:
 Source: consultants.md "Security — Findings — [Major]" item 1.', NULL, '2026-05-19 13:14:12', '2026-05-19 13:14:12', '2026-05-19 13:14:12', NULL, '3511c5e7731f568de7af33c1970ad97e', 1) ON CONFLICT(hash) DO NOTHING;
 INSERT INTO ticket_history (ticket_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('T-99', 'status', 'backlog', 'done', NULL, '2026-05-19 13:14:41', '2026-05-19 13:14:41', '2026-05-19 13:14:41', NULL, '5ff47ab0fc7fb8cb8e9e039be48ada2a', 1) ON CONFLICT(hash) DO NOTHING;
 INSERT INTO ticket_history (ticket_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('T-131', 'status', 'in_progress', 'done', NULL, '2026-05-19 13:14:41', '2026-05-19 13:14:41', '2026-05-19 13:14:41', NULL, 'a57b3fbe4e6815fcbb28691a08130801', 1) ON CONFLICT(hash) DO NOTHING;
+INSERT INTO ticket_history (ticket_id, field, old_value, new_value, changed_by, changed_at, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('T-119', 'status', 'ready', 'in_progress', NULL, '2026-05-19 14:44:43', '2026-05-19 14:44:43', '2026-05-19 14:44:43', NULL, '1d5048cf9a031c504aa3df570a7b0cae', 1) ON CONFLICT(hash) DO NOTHING;

.pql/changelog/tickets/2026-05.sql

@@ -2218,3 +2218,4 @@ INSERT INTO tickets (id, type, parent_id, title, description, status, priority,
 4. D-records updated to match reality.
 
 Source: consultants.md "Architecture — Findings — [Critical] No IPC socket server exists".', 'done', 'high', NULL, NULL, NULL, '2026-05-17 18:47:18', '2026-05-19 13:14:41', NULL, '2ad1fbf0b1b6f5b9e46d4a31d1ad830c', 1) ON CONFLICT(id) DO UPDATE SET type=excluded.type, parent_id=excluded.parent_id, title=excluded.title, description=excluded.description, status=excluded.status, priority=excluded.priority, assigned_to=excluded.assigned_to, team=excluded.team, decision_ref=excluded.decision_ref, updated_at=excluded.updated_at, deleted_at=excluded.deleted_at, hash=excluded.hash, canonical_version=excluded.canonical_version WHERE excluded.updated_at > tickets.updated_at OR (excluded.updated_at = tickets.updated_at AND excluded.hash > tickets.hash);
+INSERT INTO tickets (id, type, parent_id, title, description, status, priority, assigned_to, team, decision_ref, created_at, updated_at, deleted_at, hash, canonical_version) VALUES ('T-119', 'task', 'T-99', 'clide panel resize CLI verb (split from T-111)', 'Once T-99 lands an IPC dispatch path, register a ''panel.resize'' command that takes <slot> and <delta-or-absolute> args and calls LayoutArrangement.setSize / setEditorRatio. Keyboard parity already landed in T-111; this completes user/Claude parity per D-6.', 'in_progress', 'low', NULL, NULL, NULL, '2026-05-18 07:43:50', '2026-05-19 14:44:43', NULL, 'ac4c7a1d76836e546dac66e77ed4cb67', 1) ON CONFLICT(id) DO UPDATE SET type=excluded.type, parent_id=excluded.parent_id, title=excluded.title, description=excluded.description, status=excluded.status, priority=excluded.priority, assigned_to=excluded.assigned_to, team=excluded.team, decision_ref=excluded.decision_ref, updated_at=excluded.updated_at, deleted_at=excluded.deleted_at, hash=excluded.hash, canonical_version=excluded.canonical_version WHERE excluded.updated_at > tickets.updated_at OR (excluded.updated_at = tickets.updated_at AND excluded.hash > tickets.hash);

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

CONTRIBUTING.md

@@ -97,6 +97,9 @@ clide tail --events                  # stream every subsystem event
 clide tail --events --filter git     # stream a single subsystem
 clide pane focus editor              # drive the running app
 clide panel toggle git               # show/hide a panel
+clide panel resize sidebar --to 320  # absolute width (px)
+clide panel resize context --by -40  # relative nudge (px)
+clide panel resize editor --to 0.5   # editor split ratio (0.15–0.70)
 ```
 
 Output is JSON on stdout, one envelope per line. Streaming verbs

integration_test/app_starts_test.dart

@@ -49,7 +49,7 @@ void main() {
         'builtin.theme-picker',
         'builtin.default-layout',
       ],
-      daemonClientFactory: (log, events) => FakeDaemonClient(log: log, events: events),
+      daemonClientFactory: (log, events, _) => FakeDaemonClient(log: log, events: events),
       autoStartDaemonClient: false,
     );
     services.extensions

integration_test/extension_lifecycle_test.dart

@@ -40,7 +40,7 @@ void main() {
         'builtin.ipc-status',
         'builtin.default-layout',
       ],
-      daemonClientFactory: (log, events) => FakeDaemonClient(log: log, events: events),
+      daemonClientFactory: (log, events, _) => FakeDaemonClient(log: log, events: events),
       autoStartDaemonClient: false,
     );
     services.extensions

integration_test/theme_picker_test.dart

@@ -31,7 +31,7 @@ void main() {
         'builtin.theme-picker',
         'builtin.default-layout',
       ],
-      daemonClientFactory: (log, events) => FakeDaemonClient(log: log, events: events),
+      daemonClientFactory: (log, events, _) => FakeDaemonClient(log: log, events: events),
       autoStartDaemonClient: false,
     );
     services.extensions

lib/kernel/src/facade.dart

@@ -106,7 +106,7 @@ class KernelServices {
     Locale? initialLocale,
     List<Locale> availableLocales = const [Locale('en', 'US')],
     String? socketPath,
-    DaemonClient Function(Logger, DaemonBus)? daemonClientFactory,
+    DaemonClient Function(Logger, DaemonBus, LayoutArrangement)? daemonClientFactory,
     DaemonClient? isolateClient,
     bool autoStartDaemonClient = true,
     Toolchain? toolchain,
@@ -164,7 +164,7 @@ class KernelServices {
     );
     final ipc = isolateClient ??
         (daemonClientFactory != null
-            ? daemonClientFactory(log, events)
+            ? daemonClientFactory(log, events, arrangement)
             : DaemonClient(
                 // Legacy socket-client fallback — kept until T-127
                 // replaces it with the in-process socket loopback.

lib/main.dart

@@ -34,6 +34,8 @@ import 'package:clide/src/daemon/editor_commands.dart';
 import 'package:clide/src/daemon/files_commands.dart';
 import 'package:clide/src/daemon/git_commands.dart';
 import 'package:clide/src/daemon/pane_commands.dart';
+import 'package:clide/src/daemon/panel_commands.dart';
+import 'package:clide/src/daemon/panel_resizer_kernel.dart';
 import 'package:clide/src/daemon/pql_commands.dart';
 import 'package:clide/src/editor/registry.dart' show EditorRegistry;
 import 'package:clide/src/git/client.dart';
@@ -81,6 +83,7 @@ Future<void> main() async {
 
   DaemonClient? ipcClient;
   DaemonBus? daemonBus;
+  LayoutArrangement? kernelArrangement;
   // IPC socket server (T-99 / T-124, per D-70/71/72). One server per
   // workspace; restarted when the active project switches because the
   // socket path is workspace-derived. The local DaemonClient connects
@@ -137,7 +140,12 @@ Future<void> main() async {
     }
   }
 
-  DaemonDispatcher buildDispatcher(DaemonBus events, Toolchain tc, Directory workRoot) {
+  DaemonDispatcher buildDispatcher(
+    DaemonBus events,
+    Toolchain tc,
+    Directory workRoot,
+    LayoutArrangement arrangement,
+  ) {
     final dispatcher = DaemonDispatcher();
     final eventSink = _BusEventSink(events);
     final paneRegistry = PaneRegistry(events: eventSink);
@@ -150,6 +158,7 @@ Future<void> main() async {
     registerGitCommands(dispatcher, gitClient, eventSink);
     final pql = PqlClient(workDir: workRoot, toolchain: tc);
     registerPqlCommands(dispatcher, pql);
+    registerPanelCommands(dispatcher, ArrangementPanelResizer(arrangement));
     registerArgvUnwrap(dispatcher);
     return dispatcher;
   }
@@ -163,10 +172,11 @@ Future<void> main() async {
     toolchain: toolchain,
     daemonClientFactory: kIsWeb
         ? null
-        : (log, events) {
+        : (log, events, arrangement) {
             daemonBus = events;
+            kernelArrangement = arrangement;
             final workRoot = FilesService.atCwd(events: _BusEventSink(events)).root;
-            final dispatcher = buildDispatcher(events, toolchain, workRoot);
+            final dispatcher = buildDispatcher(events, toolchain, workRoot, arrangement);
             // Build the client at the workspace's socket path. The
             // server is started below (swapIpcServer) which the
             // client will then auto-connect to via its reconnect
@@ -187,8 +197,10 @@ Future<void> main() async {
     onProjectOpen: kIsWeb
         ? null
         : (path) async {
-            if (daemonBus == null) return;
+            final bus = daemonBus;
-            final dispatcher = buildDispatcher(daemonBus!, toolchain, Directory(path));
+            final arrangement = kernelArrangement;
+            if (bus == null || arrangement == null) return;
+            final dispatcher = buildDispatcher(bus, toolchain, Directory(path), arrangement);
             await swapIpcServer(dispatcher, Directory(path));
           },
   );

lib/src/daemon/panel_commands.dart

@@ -0,0 +1,162 @@
+/// Registers panel.* command handlers on a [DaemonDispatcher].
+///
+/// Verb list (T-119):
+///   panel.resize
+///
+/// Mirrors the keyboard-driven resize that landed in T-111
+/// (`lib/kernel/src/panels/drag_resize.dart`): the CLI verb is the
+/// other half of D-6's user/Claude parity for panel sizing.
+///
+/// Kept Flutter-free so test/daemon/ stays under `dart test` (not
+/// `flutter test`). The kernel-side bridge that wraps
+/// `LayoutArrangement` lives in
+/// `lib/src/daemon/panel_resizer_kernel.dart`.
+library;
+
+import '../ipc/envelope.dart';
+import '../ipc/schema_v1.dart';
+import 'dispatcher.dart';
+
+/// Pluggable backend the CLI/IPC layer drives. Kernel-side
+/// implementation wraps `LayoutArrangement`; tests substitute an
+/// in-memory fake.
+abstract class PanelResizer {
+  /// Apply an absolute pixel size to [slot]. Returns false when
+  /// the slot is unknown.
+  bool setSlotSize(String slot, double size);
+
+  /// Bump [slot]'s current size by a raw delta (px). Sign convention
+  /// matches the drag/keyboard handlers from T-111 — positive deltas
+  /// grow the slot from its natural edge; right-edge slots flip the
+  /// sign internally. Returns false when the slot is unknown or has
+  /// no current size.
+  bool bumpSlotSize(String slot, double rawDelta);
+
+  /// Set the absolute editor / bottom-panel split ratio. The kernel
+  /// clamps to its supported range (0.15..0.70 today).
+  void setEditorRatio(double ratio);
+
+  /// Bump the editor split ratio by [delta] (additive, post-clamp).
+  void bumpEditorRatio(double delta);
+
+  double? currentSlotSize(String slot);
+  double get currentEditorRatio;
+}
+
+/// Reserved slot name that routes to [PanelResizer.setEditorRatio] /
+/// [PanelResizer.bumpEditorRatio] instead of [PanelResizer.setSlotSize].
+const String editorSplitSlot = 'editor';
+
+void registerPanelCommands(DaemonDispatcher d, PanelResizer resizer) {
+  d.register('panel.resize', (req) => _resize(req, resizer));
+}
+
+Future<IpcResponse> _resize(IpcRequest req, PanelResizer r) async {
+  final view = _ResizeArgs.from(req.args);
+  if (view.slot == null || view.slot!.isEmpty) {
+    return _userErr(req.id, 'slot is required (e.g. "sidebar", "context", "$editorSplitSlot")');
+  }
+  if (!view.hasTo && !view.hasBy) {
+    return _userErr(req.id, 'one of `to` (absolute) or `by` (delta) is required');
+  }
+  if (view.hasTo && view.hasBy) {
+    return _userErr(req.id, 'pass only one of `to` and `by`');
+  }
+  final value = view.value;
+  if (value == null) {
+    return _userErr(req.id, '${view.hasTo ? "to" : "by"} must be numeric');
+  }
+  final slot = view.slot!;
+
+  if (slot == editorSplitSlot) {
+    if (view.hasTo) {
+      r.setEditorRatio(value);
+    } else {
+      r.bumpEditorRatio(value);
+    }
+    return IpcResponse.ok(id: req.id, data: {
+      'slot': slot,
+      'ratio': r.currentEditorRatio,
+    });
+  }
+
+  final ok = view.hasTo ? r.setSlotSize(slot, value) : r.bumpSlotSize(slot, value);
+  if (!ok) {
+    return _notFound(req.id, 'no such slot: $slot');
+  }
+  return IpcResponse.ok(id: req.id, data: {
+    'slot': slot,
+    'size': r.currentSlotSize(slot),
+  });
+}
+
+/// Tiny adapter that lifts `panel.resize` arguments out of either
+/// the direct call shape (`{slot: ..., to: ...}`) or the argv-
+/// translator shape (`{positional: [slot], flags: {to: '...'}}`).
+/// Until T-120 formalises a shared schema, individual commands carry
+/// the lift themselves.
+class _ResizeArgs {
+  _ResizeArgs._({
+    required this.slot,
+    required this.hasTo,
+    required this.hasBy,
+    required this.value,
+  });
+
+  final String? slot;
+  final bool hasTo;
+  final bool hasBy;
+  final double? value;
+
+  factory _ResizeArgs.from(Map<String, Object?> args) {
+    String? slot;
+    final rawSlot = args['slot'];
+    if (rawSlot is String) slot = rawSlot;
+    final positional = args['positional'];
+    if (slot == null && positional is List && positional.isNotEmpty) {
+      slot = positional.first.toString();
+    }
+    final flags = args['flags'];
+    final flagsMap = flags is Map ? flags : const <Object?, Object?>{};
+    final hasTo = args.containsKey('to') || flagsMap.containsKey('to');
+    final hasBy = args.containsKey('by') || flagsMap.containsKey('by');
+    final raw = args.containsKey('to')
+        ? args['to']
+        : args.containsKey('by')
+            ? args['by']
+            : flagsMap.containsKey('to')
+                ? flagsMap['to']
+                : flagsMap['by'];
+    return _ResizeArgs._(
+      slot: slot,
+      hasTo: hasTo,
+      hasBy: hasBy,
+      value: _coerceNum(raw),
+    );
+  }
+
+  static double? _coerceNum(Object? v) {
+    if (v is num) return v.toDouble();
+    if (v is String) return double.tryParse(v);
+    return null;
+  }
+}
+
+IpcResponse _userErr(String id, String message, {String? hint}) => IpcResponse.err(
+      id: id,
+      error: IpcError(
+        code: IpcExitCode.userError,
+        kind: IpcErrorKind.userError,
+        message: message,
+        hint: hint,
+      ),
+    );
+
+IpcResponse _notFound(String id, String message) => IpcResponse.err(
+      id: id,
+      error: IpcError(
+        code: IpcExitCode.notFound,
+        kind: IpcErrorKind.notFound,
+        message: message,
+      ),
+    );

lib/src/daemon/panel_resizer_kernel.dart

@@ -0,0 +1,49 @@
+/// Kernel-side [PanelResizer] that drives [LayoutArrangement] for
+/// the `panel.resize` IPC verb (T-119).
+///
+/// Lives in `lib/src/daemon/` next to the other dispatcher wiring,
+/// not `lib/kernel/`, because it bridges the Flutter-bound kernel
+/// state into the Flutter-free `panel_commands.dart` surface. Same
+/// rationale as the `_BusEventSink` in main.dart: the daemon layer
+/// owns the adapter, the kernel layer owns the data.
+library;
+
+import 'package:clide/kernel/src/panels/arrangement.dart';
+import 'package:clide/kernel/src/panels/drag_resize.dart' show bumpedSlotSize;
+import 'package:clide/kernel/src/panels/slot_id.dart';
+import 'package:clide/src/daemon/panel_commands.dart';
+
+class ArrangementPanelResizer implements PanelResizer {
+  ArrangementPanelResizer(this._a);
+
+  final LayoutArrangement _a;
+
+  @override
+  bool setSlotSize(String slot, double size) {
+    final id = SlotId(slot);
+    if (_a.sizeOf(id) == null) return false;
+    _a.setSize(id, size);
+    return true;
+  }
+
+  @override
+  bool bumpSlotSize(String slot, double rawDelta) {
+    final id = SlotId(slot);
+    final current = _a.sizeOf(id);
+    if (current == null) return false;
+    _a.setSize(id, bumpedSlotSize(slot: id, current: current, rawDelta: rawDelta));
+    return true;
+  }
+
+  @override
+  void setEditorRatio(double ratio) => _a.setEditorRatio(ratio);
+
+  @override
+  void bumpEditorRatio(double delta) => _a.setEditorRatio(_a.editorRatio + delta);
+
+  @override
+  double? currentSlotSize(String slot) => _a.sizeOf(SlotId(slot));
+
+  @override
+  double get currentEditorRatio => _a.editorRatio;
+}

test/daemon/panel_commands_test.dart

@@ -0,0 +1,169 @@
+/// Tests for the `panel.*` command handlers (T-119).
+///
+/// Uses an in-memory [PanelResizer] fake so the dispatch surface can
+/// be exercised under `dart test` without pulling Flutter into the
+/// build (the live kernel resizer wraps `LayoutArrangement`, which is
+/// Flutter-bound; tests for that live in
+/// `test/kernel/src/panels/arrangement_test.dart`).
+library;
+
+import 'package:clide/clide.dart';
+import 'package:clide/src/daemon/panel_commands.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group('panel.resize dispatch', () {
+    late DaemonDispatcher dispatcher;
+    late _FakeResizer resizer;
+
+    setUp(() {
+      resizer = _FakeResizer(
+        slots: {'sidebar': 200, 'context': 240, 'workspace': 800},
+        editorRatio: 0.35,
+      );
+      dispatcher = DaemonDispatcher();
+      registerPanelCommands(dispatcher, resizer);
+    });
+
+    Future<IpcResponse> call(Map<String, Object?> args) {
+      return dispatcher.dispatch(IpcRequest(id: '1', cmd: 'panel.resize', args: args));
+    }
+
+    test('rejects a request with no slot', () async {
+      final r = await call(const {'to': 220});
+      expect(r.ok, isFalse);
+      expect(r.error!.kind, 'user_error');
+      expect(r.error!.message, contains('slot'));
+    });
+
+    test('rejects a request with neither `to` nor `by`', () async {
+      final r = await call(const {'slot': 'sidebar'});
+      expect(r.ok, isFalse);
+      expect(r.error!.kind, 'user_error');
+      expect(r.error!.message, contains('to'));
+      expect(r.error!.message, contains('by'));
+    });
+
+    test('rejects a request with both `to` and `by`', () async {
+      final r = await call(const {'slot': 'sidebar', 'to': 200, 'by': 10});
+      expect(r.ok, isFalse);
+      expect(r.error!.kind, 'user_error');
+      expect(r.error!.message, contains('only one'));
+    });
+
+    test('rejects a non-numeric `to`', () async {
+      final r = await call(const {'slot': 'sidebar', 'to': 'lots'});
+      expect(r.ok, isFalse);
+      expect(r.error!.kind, 'user_error');
+      expect(r.error!.message, contains('numeric'));
+    });
+
+    test('rejects an unknown slot with not-found', () async {
+      final r = await call(const {'slot': 'nonsense', 'to': 100});
+      expect(r.ok, isFalse);
+      expect(r.error!.kind, 'not_found');
+      expect(r.error!.message, contains('nonsense'));
+    });
+
+    test('absolute `to` sets the slot size and echoes the result', () async {
+      final r = await call(const {'slot': 'sidebar', 'to': 320});
+      expect(r.ok, isTrue, reason: r.error?.message);
+      expect(r.data['slot'], 'sidebar');
+      expect(r.data['size'], 320);
+      expect(resizer.slots['sidebar'], 320);
+    });
+
+    test('relative `by` bumps the slot through PanelResizer.bumpSlotSize', () async {
+      final r = await call(const {'slot': 'sidebar', 'by': 25});
+      expect(r.ok, isTrue, reason: r.error?.message);
+      expect(resizer.slots['sidebar'], 200 + 25);
+      expect(resizer.lastBumpSlot, 'sidebar');
+      expect(resizer.lastBumpDelta, 25);
+    });
+
+    test('editor slot routes to setEditorRatio', () async {
+      final r = await call(const {'slot': 'editor', 'to': 0.55});
+      expect(r.ok, isTrue, reason: r.error?.message);
+      expect(r.data['ratio'], 0.55);
+      expect(resizer.editorRatio, 0.55);
+    });
+
+    test('editor slot with `by` routes to bumpEditorRatio', () async {
+      final r = await call(const {'slot': 'editor', 'by': 0.1});
+      expect(r.ok, isTrue, reason: r.error?.message);
+      expect(resizer.editorRatio, closeTo(0.45, 1e-9));
+    });
+
+    group('argv-translator shape', () {
+      test('positional[0] supplies the slot and flags carry to/by as strings', () async {
+        final r = await call(const {
+          'positional': ['sidebar'],
+          'flags': {'to': '275'},
+        });
+        expect(r.ok, isTrue, reason: r.error?.message);
+        expect(resizer.slots['sidebar'], 275);
+      });
+
+      test('argv shape `by` parses to a delta', () async {
+        final r = await call(const {
+          'positional': ['context'],
+          'flags': {'by': '-30'},
+        });
+        expect(r.ok, isTrue, reason: r.error?.message);
+        expect(resizer.lastBumpSlot, 'context');
+        expect(resizer.lastBumpDelta, -30);
+      });
+
+      test('argv shape with neither flag still surfaces a user error', () async {
+        final r = await call(const {
+          'positional': ['sidebar'],
+          'flags': <String, Object?>{},
+        });
+        expect(r.ok, isFalse);
+        expect(r.error!.kind, 'user_error');
+      });
+    });
+  });
+}
+
+class _FakeResizer implements PanelResizer {
+  _FakeResizer({required this.slots, required this.editorRatio});
+
+  final Map<String, double> slots;
+  double editorRatio;
+
+  String? lastBumpSlot;
+  double? lastBumpDelta;
+
+  @override
+  bool setSlotSize(String slot, double size) {
+    if (!slots.containsKey(slot)) return false;
+    slots[slot] = size;
+    return true;
+  }
+
+  @override
+  bool bumpSlotSize(String slot, double rawDelta) {
+    if (!slots.containsKey(slot)) return false;
+    lastBumpSlot = slot;
+    lastBumpDelta = rawDelta;
+    slots[slot] = slots[slot]! + rawDelta;
+    return true;
+  }
+
+  @override
+  void setEditorRatio(double ratio) {
+    editorRatio = ratio;
+  }
+
+  @override
+  void bumpEditorRatio(double delta) {
+    editorRatio += delta;
+  }
+
+  @override
+  double? currentSlotSize(String slot) => slots[slot];
+
+  @override
+  double get currentEditorRatio => editorRatio;
+}

test/helpers/kernel_fixture.dart

@@ -32,7 +32,7 @@ class KernelFixture {
       preloadNamespaces: catalogs.keys.toList(),
       defaultLocale: defaultLocale,
       initialLocale: initialLocale,
-      daemonClientFactory: (log, events) {
+      daemonClientFactory: (log, events, _) {
         fake = FakeDaemonClient(log: log, events: events);
         return fake!;
       },

test/kernel/src/panels/panel_resizer_kernel_test.dart

@@ -0,0 +1,58 @@
+/// Tests the kernel-side bridge that connects the Flutter-free
+/// `panel.resize` handler (T-119) to the live [LayoutArrangement].
+/// The handler-side tests live in
+/// `test/daemon/panel_commands_test.dart` against an in-memory fake.
+library;
+
+import 'package:clide/kernel/kernel.dart';
+import 'package:clide/src/daemon/panel_resizer_kernel.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  group('ArrangementPanelResizer', () {
+    late LayoutArrangement arrangement;
+    late ArrangementPanelResizer r;
+
+    setUp(() {
+      arrangement = LayoutArrangement()..applyPreset(classicPreset());
+      r = ArrangementPanelResizer(arrangement);
+    });
+
+    test('setSlotSize forwards to LayoutArrangement.setSize and clamps', () {
+      final ok = r.setSlotSize('sidebar', 10000);
+      expect(ok, isTrue);
+      expect(arrangement.sizeOf(Slots.sidebar), arrangement.maxSizeOf(Slots.sidebar));
+      expect(r.currentSlotSize('sidebar'), arrangement.sizeOf(Slots.sidebar));
+    });
+
+    test('setSlotSize returns false for an unknown slot', () {
+      expect(r.setSlotSize('does-not-exist', 250), isFalse);
+    });
+
+    test('bumpSlotSize applies the T-111 sign-flip on context panel', () {
+      final start = arrangement.sizeOf(Slots.contextPanel)!;
+      final ok = r.bumpSlotSize('context', 40);
+      expect(ok, isTrue);
+      // Context sits on the right edge — positive delta shrinks it.
+      expect(arrangement.sizeOf(Slots.contextPanel), lessThan(start));
+    });
+
+    test('bumpSlotSize returns false for an unknown slot', () {
+      expect(r.bumpSlotSize('nope', 5), isFalse);
+    });
+
+    test('setEditorRatio + currentEditorRatio round-trip through arrangement', () {
+      r.setEditorRatio(0.5);
+      expect(arrangement.editorRatio, 0.5);
+      expect(r.currentEditorRatio, 0.5);
+    });
+
+    test('bumpEditorRatio adds to current ratio (kernel re-clamps)', () {
+      r.setEditorRatio(0.4);
+      r.bumpEditorRatio(0.2);
+      expect(arrangement.editorRatio, closeTo(0.60, 1e-9));
+      r.bumpEditorRatio(1.0); // out-of-range; kernel clamps to 0.70
+      expect(arrangement.editorRatio, 0.70);
+    });
+  });
+}