fix(workspace): normalize websocket headers for reverse proxies and show detailed disconnect reason

internal/api/server.go

@@ -1585,6 +1585,18 @@ func (s *Server) handleReorderListItems(w http.ResponseWriter, r *http.Request)
 }
 
 func (s *Server) handleWebSocket(w http.ResponseWriter, r *http.Request) {
+	// Some corporate proxies and reverse proxies (e.g. OpenResty/Nginx or HTTP/2 intermediaries)
+	// strip or alter the Connection header (e.g. "close" or missing) while passing
+	// Sec-WebSocket-Key or Upgrade: websocket. Normalize it so Gorilla Upgrader succeeds.
+	if r.Header.Get("Sec-Websocket-Key") != "" {
+		if !strings.Contains(strings.ToLower(r.Header.Get("Connection")), "upgrade") {
+			r.Header.Set("Connection", "Upgrade")
+		}
+		if !strings.Contains(strings.ToLower(r.Header.Get("Upgrade")), "websocket") {
+			r.Header.Set("Upgrade", "websocket")
+		}
+	}
+
 	roomID := chi.URLParam(r, "listId")
 	if roomID == "" {
 		roomID = chi.URLParam(r, "spaceId")