Revert "feat(request-details): implement observability settings and enhance request detail tracking"

This reverts commit cbabf5547c.

src/lib/usageDb.js

@@ -511,6 +511,3 @@ export async function getUsageStats() {
 
   return stats;
 }
-
-// Re-export request details functions from new SQLite-based module
-export { saveRequestDetail, getRequestDetails, getRequestDetailById } from "./requestDetailsDb.js";