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/locales/zh/navigation.json

@@ -8,6 +8,8 @@
     "orchestrator": "编排器",
     "loops": "循环监控",
     "issues": "问题",
+    "issueQueue": "问题队列",
+    "issueDiscovery": "问题发现",
     "skills": "技能",
     "commands": "命令",
     "memory": "记忆",