feat: add tests and implementation for issue discovery and queue pages

- Implemented `DiscoveryPage` with session management and findings display.
- Added tests for `DiscoveryPage` to ensure proper rendering and functionality.
- Created `QueuePage` for managing issue execution queues with stats and actions.
- Added tests for `QueuePage` to verify UI elements and translations.
- Introduced `useIssues` hooks for fetching and managing issue data.
- Added loading skeletons and error handling for better user experience.
- Created `vite-env.d.ts` for TypeScript support in Vite environment.

ccw/frontend/src/components/layout/Sidebar.tsx

@@ -12,6 +12,8 @@ import {
   Workflow,
   RefreshCw,
   AlertCircle,
+  ListTodo,
+  Search,
   Sparkles,
   Terminal,
   Brain,
@@ -25,8 +27,6 @@ import {
   GitFork,
   Shield,
   History,
-  Folder,
-  Network,
 } from 'lucide-react';
 import { cn } from '@/lib/utils';
 import { Button } from '@/components/ui/Button';
@@ -60,13 +60,13 @@ const navItemDefinitions: Omit<NavItem, 'label'>[] = [
   { path: '/orchestrator', icon: Workflow },
   { path: '/loops', icon: RefreshCw },
   { path: '/issues', icon: AlertCircle },
+  { path: '/issues/queue', icon: ListTodo },
+  { path: '/issues/discovery', icon: Search },
   { path: '/skills', icon: Sparkles },
   { path: '/commands', icon: Terminal },
   { path: '/memory', icon: Brain },
   { path: '/prompts', icon: History },
   { path: '/hooks', icon: GitFork },
-  { path: '/explorer', icon: Folder },
-  { path: '/graph', icon: Network },
   { path: '/settings', icon: Settings },
   { path: '/settings/rules', icon: Shield },
   { path: '/help', icon: HelpCircle },
@@ -110,13 +110,13 @@ export function Sidebar({
       '/orchestrator': 'main.orchestrator',
       '/loops': 'main.loops',
       '/issues': 'main.issues',
+      '/issues/queue': 'main.issueQueue',
+      '/issues/discovery': 'main.issueDiscovery',
       '/skills': 'main.skills',
       '/commands': 'main.commands',
       '/memory': 'main.memory',
       '/prompts': 'main.prompts',
       '/hooks': 'main.hooks',
-      '/explorer': 'main.explorer',
-      '/graph': 'main.graph',
       '/settings': 'main.settings',
       '/settings/rules': 'main.rules',
       '/help': 'main.help',