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/pages/index.ts

@@ -12,6 +12,8 @@ export { HistoryPage } from './HistoryPage';
 export { OrchestratorPage } from './orchestrator';
 export { LoopMonitorPage } from './LoopMonitorPage';
 export { IssueManagerPage } from './IssueManagerPage';
+export { QueuePage } from './QueuePage';
+export { DiscoveryPage } from './DiscoveryPage';
 export { SkillsManagerPage } from './SkillsManagerPage';
 export { CommandsManagerPage } from './CommandsManagerPage';
 export { MemoryPage } from './MemoryPage';