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

- Added new observability settings in the dashboard for max records, batch size, flush interval, and max JSON size.
- Introduced `extractRequestConfig` function to capture full request configurations.
- Enhanced error handling by saving detailed request information on failures.
- Updated usage tracking to include new token metrics.
- Modified streaming functions to support detailed content and reasoning tracking.

src/lib/usageDb.js

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