fix: resolve frontend module resolution errors

- Remove broken DetailStat and StatCard exports from shared/index.ts
- Fix message-detail-view import to message-detail
- Create missing ai-status-badge component with status-based styling

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

services/frontend/src/app/(dashboard)/messages/page.tsx

@@ -4,7 +4,7 @@ import { useCallback, useEffect, useState } from "react";
 import { useSearchParams, useRouter } from "next/navigation";
 import { Flag, Image, Loader2, RefreshCw, Search } from "lucide-react";
 import { MessageList } from "@/components/messages/message-list";
-import { MessageDetailView } from "@/components/messages/message-detail-view";
+import { MessageDetail } from "@/components/messages/message-detail";
 import { SearchOverlay } from "@/components/messages/search-overlay";
 import { extractFirstImage } from "@/components/messages/message-card";
 import { SubNav } from "@/components/layout/sub-nav";
@@ -227,7 +227,7 @@ export default function MessagesPage() {
                   >
                     ← Back to list
                   </button>
-                  <MessageDetailView
+                  <MessageDetail
                     message={detailMessage}
                     attachments={detailAttachments}
                   />