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/notifications.json

@@ -1,5 +1,6 @@
 {
   "title": "Notifications",
+  "close": "Close notifications",
   "empty": "No notifications",
   "emptyHint": "Notifications will appear here",
   "markAllRead": "Mark Read",
@@ -14,5 +15,38 @@
   "daysAgo": "{0}d ago",
   "oneMinuteAgo": "1m ago",
   "oneHourAgo": "1h ago",
-  "oneDayAgo": "1d ago"
+  "oneDayAgo": "1d ago",
+  "sources": {
+    "system": "System",
+    "websocket": "WebSocket",
+    "cli": "CLI",
+    "workflow": "Workflow",
+    "user": "User",
+    "external": "External"
+  },
+  "priorities": {
+    "low": "Low",
+    "medium": "Medium",
+    "high": "High",
+    "critical": "Critical"
+  },
+  "attachments": {
+    "image": "Image",
+    "code": "Code",
+    "file": "File",
+    "data": "Data",
+    "download": "Download"
+  },
+  "actions": {
+    "loading": "Loading...",
+    "success": "Done",
+    "retry": "Retry"
+  },
+  "timestamps": {
+    "today": "Today",
+    "yesterday": "Yesterday",
+    "atTime": "at {0}"
+  },
+  "markAsRead": "Mark as read",
+  "markAsUnread": "Mark as unread"
 }