refactor(websocket): migrate endpoint from /api/ws to /ws/sync

- Update WebSocket connection URL in admin.ts to use new /ws/sync endpoint
- Update API documentation in bruno collection to reflect new WebSocket route
- Standardizes WebSocket routing under /ws/ path prefix for better API organization

This change improves API structure consistency and makes WebSocket endpoints
more discoverable and manageable under a dedicated path hierarchy.

web/src/admin.ts

@@ -337,7 +337,7 @@ let scanPollInterval: ReturnType<typeof setInterval> | undefined = undefined;
 let scanWs: WebSocket | null = null;
 function connectScanWebSocket(): void {
   const protocol = window.location.protocol === "https:" ? "wss:" : "ws:";
-  const wsUrl = `${protocol}//${window.location.host}/api/ws`;
+  const wsUrl = `${protocol}//${window.location.host}/ws/sync`;
 
   scanWs = new WebSocket(wsUrl);