fix: build desktop session share links on the linked server (#1350)

plugins/remote-desktop/src/frontend/GuacamoleApp.tsx

@@ -639,6 +639,8 @@ const GuacamoleAppInner = React.forwardRef<
                   sessionId: guacamoleConnectionId,
                   protocol: resolvedProtocol,
                   tabInstanceId: tabId,
+                  origin:
+                    sessionLookup?.origin === "remote" ? "remote" : "local",
                 }
               : undefined
           }

plugins/remote-desktop/src/frontend/GuacamoleToolbar.tsx

@@ -64,6 +64,8 @@ export interface RemoteDesktopToolbarContext {
   sessionId: string | null;
   protocol: "rdp" | "vnc" | "telnet";
   tabInstanceId?: string;
+  /** The backend the session runs on. */
+  origin?: "local" | "remote";
 }
 
 const MODIFIER_KEYSYMS = {