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/en/navigation.json

@@ -8,6 +8,8 @@
     "orchestrator": "Orchestrator",
     "loops": "Loop Monitor",
     "issues": "Issues",
+    "issueQueue": "Issue Queue",
+    "issueDiscovery": "Issue Discovery",
     "skills": "Skills",
     "commands": "Commands",
     "memory": "Memory",