feat: add CLI Viewer Page with multi-pane layout and state management

- Implemented the CliViewerPage component for displaying CLI outputs in a configurable multi-pane layout.
- Integrated Zustand for state management, allowing for dynamic layout changes and tab management.
- Added layout options: single, split horizontal, split vertical, and 2x2 grid.
- Created viewerStore for managing layout, panes, and tabs, including actions for adding/removing panes and tabs.
- Added CoordinatorPage barrel export for easier imports.

ccw/frontend/src/router.tsx

@@ -31,7 +31,6 @@ import {
   McpManagerPage,
   EndpointsPage,
   InstallationsPage,
-  ExecutionMonitorPage,
   HookManagerPage,
   RulesManagerPage,
   PromptHistoryPage,
@@ -39,6 +38,7 @@ import {
   GraphExplorerPage,
   CodexLensManagerPage,
   ApiSettingsPage,
+  CliViewerPage,
 } from '@/pages';
 
 /**
@@ -91,14 +91,14 @@ const routes: RouteObject[] = [
         path: 'coordinator',
         element: <CoordinatorPage />,
       },
-      {
-        path: 'executions',
-        element: <ExecutionMonitorPage />,
-      },
       {
         path: 'loops',
         element: <LoopMonitorPage />,
       },
+      {
+        path: 'cli-viewer',
+        element: <CliViewerPage />,
+      },
       {
         path: 'issues',
         element: <IssueHubPage />,
@@ -206,8 +206,8 @@ export const ROUTES = {
   HISTORY: '/history',
   ORCHESTRATOR: '/orchestrator',
   COORDINATOR: '/coordinator',
-  EXECUTIONS: '/executions',
   LOOPS: '/loops',
+  CLI_VIEWER: '/cli-viewer',
   ISSUES: '/issues',
   // Legacy issue routes - use ISSUES with ?tab parameter instead
   ISSUE_QUEUE: '/issues?tab=queue',